Compare commits
| Author | SHA1 | Date | |
|---|---|---|---|
  Florian WaltherandClaude Opus 5.5
|
f66cf538c0 | ||
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Florian WaltherandClaude Opus 5.5
|
443367f66f | ||
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Florian WaltherandClaude Opus 5.5
|
9fe8b06fba | ||
|
Florian WaltherandClaude Opus 5.5
|
22ce8c00d4 | ||
|
Florian Walther
|
fb94e98da5 |
No files matched your search
@@ -1,2 +1,3 @@
|
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gosh
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dist/
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packaging/man/gosh.1.gz
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@@ -12,6 +12,8 @@ before:
|
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hooks:
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- go mod tidy
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- go test ./...
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# Man page with the release version, gzipped for /usr/share/man
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- sh -c 'sed "s/@VERSION@/{{ .Version }}/" packaging/man/gosh.1 | gzip -9n > packaging/man/gosh.1.gz'
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builds:
|
||||
- id: gosh
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@@ -50,6 +52,10 @@ archives:
|
||||
- src: README.md
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info:
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mode: 0644
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||||
- src: packaging/man/gosh.1.gz
|
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dst: man/gosh.1.gz
|
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info:
|
||||
mode: 0644
|
||||
|
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nfpms:
|
||||
- id: gosh
|
||||
@@ -75,6 +81,10 @@ nfpms:
|
||||
dst: /usr/share/doc/gosh/README.md
|
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file_info:
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mode: 0644
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||||
- src: packaging/man/gosh.1.gz
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dst: /usr/share/man/man1/gosh.1.gz
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file_info:
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mode: 0644
|
||||
scripts:
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||||
postinstall: packaging/scripts/postinstall.sh
|
||||
postremove: packaging/scripts/postremove.sh
|
||||
|
||||
@@ -1,8 +1,8 @@
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||||
`gosh` eine einfache Shell, geschrieben in golang.
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`gosh` eine Shell, in golang geschrieben.
|
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|
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```
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gosh - Go Shell
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Version: 0.2.1 (branch: main, commit: 03e791c)
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Version: 0.13.0 (branch: main, commit: f79fb0b)
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Built-in commands:
|
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cd [dir] - Change directory (cd with no args goes to home)
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@@ -11,8 +11,10 @@ Built-in commands:
|
||||
exit [code] - Exit shell with status code (default: $?)
|
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quit [code] - Quit shell with status code (default: $?)
|
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set VAR=val - Set environment variable
|
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set -- args - Set the positional parameters $1, $2, ...
|
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export VAR=val - Export environment variable
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source file - Run the commands of file in this shell (also: . file)
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unset VAR - Remove a variable (unset -f name: a function)
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source file [args] - Run the commands of file in this shell (also: . file)
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jobs - List background and stopped jobs
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fg [%n] - Continue job n (default: current job) in the foreground
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bg [%n] - Continue stopped job n in the background
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@@ -22,6 +24,12 @@ Built-in commands:
|
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: - Do nothing (exit status 0)
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break [n] - Leave the innermost (or n-th) for/while/until loop
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continue [n] - Continue with the next iteration of a loop
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return [n] - Leave a function or sourced file with status n
|
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local VAR[=val] - Variable that gets its old value back when the
|
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function returns
|
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shift [n] - Remove the first n positional parameters (default 1)
|
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read [-r] [-p prompt] [VAR ...] - Read a line into variables (split
|
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at $IFS; the last one gets the rest; default $REPLY)
|
||||
help - Show this help
|
||||
|
||||
Features:
|
||||
@@ -44,8 +52,14 @@ Features:
|
||||
GOSH_COLORS='user=1;33:path=36' (keys user, root, path, error; values
|
||||
are ANSI SGR codes, empty = no color); disabled with $NO_COLOR,
|
||||
TERM=dumb or when output is not a terminal
|
||||
- Variables: name=value sets a variable (like set), name=value command
|
||||
sets it only for that command; the value is not split or expanded as
|
||||
a pattern
|
||||
- Environment variable expansion ($VAR, ${VAR}, ${VAR:-default});
|
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using an unset variable is an error, use ${VAR:-} for an empty default
|
||||
- Positional parameters: $0, $1 ... $9, ${10}, $# (count), "$@" (one
|
||||
word each), "$*" (one word), $$ (process ID); set by gosh script
|
||||
args, gosh -c command name args, functions, set -- and source
|
||||
- Command substitution: $(command) is replaced by the output of command
|
||||
(run in a subshell); unquoted it is split into words, "$(command)"
|
||||
stays one word
|
||||
@@ -53,9 +67,16 @@ Features:
|
||||
a || b (b only if a failed); $? is the exit status of the last command
|
||||
- Control structures: if cmd; then ...; elif cmd; then ...; else ...; fi,
|
||||
for x in words; do ...; done, while cmd; do ...; done, until ...,
|
||||
! cmd negates the status; they can span several lines (prompt "> ")
|
||||
case word in pattern|pattern) ...;; esac, { cmd; cmd; } groups,
|
||||
( cmd; cmd ) subshells; ! cmd negates the status; they can span
|
||||
several lines (prompt "> "), have redirections (done < file) and can
|
||||
be used in pipes (| while read l; do ...; done) and with &
|
||||
- Functions: name() { ...; } (or function name { ...; }); the arguments
|
||||
are $1, $2, ...; in pipes, & and $(...) they run in a subshell
|
||||
- Pipes (a | b) and redirections: < file, > file, >> file, 2> file,
|
||||
2>> file, 2>&1, >&2, &> file (stdout and stderr), &>> file
|
||||
2>> file, 2>&1, >&2, &> file (stdout and stderr), &>> file,
|
||||
<<EOF here-documents (<<-EOF strips tabs, <<'EOF' expands nothing),
|
||||
<<<word here-strings
|
||||
- Job control: command & runs in the background, Ctrl+Z stops the
|
||||
foreground job; jobs, fg, bg and wait manage the jobs
|
||||
- Aliases replace the first word of a command in interactive shells
|
||||
@@ -71,8 +92,8 @@ Features:
|
||||
### Aufruf
|
||||
|
||||
```
|
||||
gosh [-l] [-i] [--norc] [--noprofile] [script]
|
||||
gosh [-l] [--noprofile] -c command
|
||||
gosh [-l] [-i] [--norc] [--noprofile] [script [args ...]]
|
||||
gosh [-l] [--noprofile] -c command [name [args ...]]
|
||||
gosh -version
|
||||
```
|
||||
|
||||
@@ -80,7 +101,8 @@ gosh -version
|
||||
|------------------------|------------------------------------------------------------------|
|
||||
| `gosh` | interaktive Shell (wenn stdin ein Terminal ist) |
|
||||
| `gosh -c 'befehl'` | führt den Befehl aus und beendet sich |
|
||||
| `gosh skript.gosh` | führt das Skript Zeile für Zeile aus |
|
||||
| `gosh -c 'befehl' name a b` | wie oben, mit `$0` = `name`, `$1` = `a`, `$2` = `b` |
|
||||
| `gosh skript.gosh a b` | führt das Skript Zeile für Zeile aus, `$1` = `a`, `$2` = `b` |
|
||||
| `befehle \| gosh` | liest die Befehle von stdin |
|
||||
| `-i` | erzwingt den interaktiven Modus, auch ohne Terminal |
|
||||
| `-l`, `--login` | Login-Shell, liest die Profil-Dateien (siehe unten) |
|
||||
@@ -133,7 +155,7 @@ export PATH=$HOME/bin:$PATH
|
||||
|
||||
### Kontrollstrukturen
|
||||
|
||||
gosh kennt `if`, `for`, `while` und `until` wie `sh`, auf einer Zeile oder über mehrere Zeilen:
|
||||
gosh kennt `if`, `for`, `while`, `until`, `case`, `{ …; }` und `( … )` wie `sh`, auf einer Zeile oder über mehrere Zeilen:
|
||||
|
||||
```bash
|
||||
if [ -f ~/.goshrc ]; then
|
||||
@@ -150,13 +172,22 @@ done
|
||||
|
||||
for i in {1..5}; do echo "Durchlauf $i"; done
|
||||
|
||||
set n=3
|
||||
n=3
|
||||
while [ $n -gt 0 ]; do
|
||||
echo $n
|
||||
set n=$(expr $n - 1)
|
||||
n=$(expr $n - 1)
|
||||
done
|
||||
|
||||
until ping -c1 -W1 server >/dev/null; do sleep 1; done
|
||||
|
||||
case "$1" in
|
||||
start|run) echo "starte" ;;
|
||||
stop) echo "stoppe" ;;
|
||||
*.tar.gz) tar xzf "$1" ;;
|
||||
*) echo "unbekannt: $1" ;;
|
||||
esac
|
||||
|
||||
test -d build || { echo "kein build-Verzeichnis"; exit 1; }
|
||||
```
|
||||
|
||||
| Konstrukt | Bedeutung |
|
||||
@@ -165,17 +196,176 @@ until ping -c1 -W1 server >/dev/null; do sleep 1; done
|
||||
| `for x in wörter; do …; done` | setzt `x` nacheinander auf jedes Wort |
|
||||
| `while befehl; do …; done` | wiederholt, solange `befehl` erfolgreich ist |
|
||||
| `until befehl; do …; done` | wiederholt, bis `befehl` erfolgreich ist |
|
||||
| `case wort in muster\|muster) …;; esac` | führt den ersten Zweig aus, dessen Muster auf `wort` passt |
|
||||
| `{ befehl; befehl; }` | fasst Befehle zusammen (z. B. nach `\|\|`) |
|
||||
| `( befehl; befehl )` | führt die Befehle in einer Subshell aus |
|
||||
| `! befehl` | kehrt den Exit-Status um |
|
||||
| `break [n]`, `continue [n]` | verlässt die (n-te) Schleife bzw. springt zum nächsten Durchlauf |
|
||||
| `:` | tut nichts, Exit-Status 0 (z. B. `while :; do …; done`) |
|
||||
|
||||
- Bedingungen sind normale Befehle (auch Listen mit `&&`/`||`), meist `test` bzw. `[ … ]` (z. B. `[ -f datei ]`, `[ "$a" = b ]`, `[ $n -lt 3 ]`).
|
||||
- Die Wörter nach `for … in` werden wie Argumente expandiert: `*.go`, `{1..10}`, `$VAR`, `$(befehl)`. Ohne `in` läuft die Schleife nicht (Positionsparameter gibt es nicht).
|
||||
- Die Wörter nach `for … in` werden wie Argumente expandiert: `*.go`, `{1..10}`, `$VAR`, `$(befehl)`, `"$@"`. Ohne `in` läuft die Schleife über die Positionsparameter (`for a; do …` ist `for a in "$@"; do …`).
|
||||
- `case`: Die Muster sind Wildcards wie bei Dateinamen (`*`, `?`, `[…]`), nur passen `*` und `?` hier auch auf `/`. Mehrere Muster werden mit `|` getrennt, das `(` vor dem Muster ist optional, das `;;` im letzten Zweig auch. Zeichen in Anführungszeichen passen nur wörtlich (`"*")` passt nur auf `*`). Wie überall in gosh sind Werte von Variablen keine Muster: Nach `p='*.go'` passt `$p)` nur auf den Text `*.go`. Passt kein Muster, ist der Status 0.
|
||||
- `{ …; }`: `{` und `}` sind nur am Anfang eines Befehls Schlüsselwörter, vor dem `}` muss deshalb ein `;` oder ein Zeilenumbruch stehen. Die Befehle laufen in der Shell selbst (keine Subshell).
|
||||
- Variablen, `$(...)` und Wildcards im Rumpf werden bei jedem Durchlauf neu ersetzt.
|
||||
- Ist ein Befehl noch nicht vollständig (z. B. nach `if …; then` oder `for …` + Enter, nach `&&`, `|` oder einem `\` am Zeilenende), zeigt gosh den Fortsetzungs-Prompt `> `; Ctrl+C verwirft die angefangene Eingabe. Skripte und Startdateien lesen entsprechend weiter.
|
||||
- Ctrl+C bricht die ganze Befehlszeile ab, also auch eine Schleife (`while true; do sleep 1; done`).
|
||||
- Der Exit-Status ist der des zuletzt ausgeführten Befehls; ein `if` ohne passenden Zweig und eine Schleife ohne Durchlauf haben den Status 0.
|
||||
- Nicht unterstützt: Kontrollstrukturen in Pipes (`for …; done | sort`), mit Umleitung (`done > datei`) oder im Hintergrund (`done &`), außerdem `case`, Funktionen, `read` und Zuweisungen der Form `x=1` – Variablen setzt man mit `set x=1`, Arithmetik geht z. B. mit `$(expr $n + 1)`.
|
||||
- Arithmetik geht noch nicht mit `$((…))`, sondern z. B. mit `n=$(expr $n + 1)`.
|
||||
|
||||
### Umleitungen, Pipes und Hintergrund bei Kontrollstrukturen
|
||||
|
||||
Kontrollstrukturen lassen sich wie einfache Befehle umleiten, in Pipes verwenden und im Hintergrund starten:
|
||||
|
||||
```bash
|
||||
# Datei Zeile für Zeile lesen
|
||||
while read -r name rest; do
|
||||
echo "Name: $name"
|
||||
done < /etc/passwd
|
||||
|
||||
# Ausgabe einer Schleife sortieren bzw. umleiten
|
||||
for f in *.log; do wc -l < "$f"; done | sort -n
|
||||
if make; then echo ok; else echo kaputt; fi > build.status 2>&1
|
||||
{ date; uptime; } >> status.log
|
||||
|
||||
# Zeilen aus einer Pipe verarbeiten
|
||||
git ls-files | while read -r f; do echo "== $f"; done
|
||||
|
||||
# Schleife im Hintergrund
|
||||
for host in a b c; do ping -c1 $host; done > ping.log &
|
||||
```
|
||||
|
||||
- Umleitungen nach `done`, `fi`, `esac`, `}` und `)` gelten für alle Befehle darin. Die Kontrollstruktur läuft dabei in der Shell selbst, Variablen aus `while read x; do …; done < datei` sind danach also gesetzt.
|
||||
- In einer Pipe und im Hintergrund (`&`) läuft eine Kontrollstruktur (wie in `sh`) in einer Subshell, einem eigenen gosh-Prozess, weil alle Teile einer Pipe gleichzeitig laufen. Variablen, die dort gesetzt werden, gelten danach nicht mehr: Nach `ls | while read f; do n=$f; done` ist `n` nicht gesetzt. Die Subshell kennt die Funktionen und Positionsparameter der Shell.
|
||||
- Auch Listen lassen sich in den Hintergrund schicken: `make && make install &` läuft als ein Job in einer Subshell.
|
||||
- Mit Ctrl+C wird die ganze Pipe abgebrochen, auch eine Endlosschleife wie `while true; do date; sleep 1; done | tee log`.
|
||||
|
||||
### Subshells
|
||||
|
||||
`( befehle )` führt Befehle in einer Subshell aus, einem eigenen gosh-Prozess. Änderungen an Verzeichnis, Variablen und Funktionen gelten nur dort:
|
||||
|
||||
```bash
|
||||
(cd /tmp && tar xzf ~/paket.tar.gz) # danach ist man noch im alten Verzeichnis
|
||||
(export LANG=C; sort datei)
|
||||
(exit 3); echo $? # 3
|
||||
(cd build && make) > build.log 2>&1
|
||||
```
|
||||
|
||||
- `exit` beendet nur die Subshell, ihr Exit-Status ist der des letzten Befehls bzw. von `exit`.
|
||||
- Die Subshell bekommt alle Variablen (in gosh sind alle exportiert), die Funktionen und die Positionsparameter. Aliase gelten dort nicht (wie in Skripten).
|
||||
- `{ …; }` fasst dagegen Befehle zusammen, ohne eine Subshell zu starten.
|
||||
- `(` und `)` sind Operatoren: Ein Wort wie `a(b)` ist ein Syntaxfehler, Klammern als Text brauchen Anführungszeichen oder `\` (`echo "(a)"`, `find . \( -name x \)`).
|
||||
|
||||
### Funktionen
|
||||
|
||||
```bash
|
||||
# Definition (auch: function gruss { … })
|
||||
gruss() {
|
||||
local name=${1:-Welt} # local: nur in der Funktion
|
||||
echo "Hallo $name"
|
||||
}
|
||||
|
||||
gruss # Hallo Welt
|
||||
gruss Flo # Hallo Flo
|
||||
gruss Flo > datei # Umleitungen gelten für alle Befehle der Funktion
|
||||
gruss Flo | tr a-z A-Z # auch in Pipes
|
||||
x=$(gruss Flo)
|
||||
|
||||
ist_root() {
|
||||
[ "$(id -u)" = 0 ] && return 0
|
||||
return 1
|
||||
}
|
||||
ist_root || echo "kein root"
|
||||
|
||||
# Die Funktion liest von stdin
|
||||
zeilen() {
|
||||
while read -r zeile; do echo "> $zeile"; done
|
||||
}
|
||||
zeilen < /etc/hostname
|
||||
ls | zeilen
|
||||
```
|
||||
|
||||
- Eine Funktion wird mit `name() { …; }`, `name () { …; }` oder `function name { …; }` definiert. Der Rumpf ist ein zusammengesetzter Befehl, meist `{ …; }`, aber auch `if`, `for`, `while` oder `case` sind möglich. Die Definition darf über mehrere Zeilen gehen.
|
||||
- Die Argumente des Aufrufs sind in der Funktion `$1`, `$2`, …, `$#` und `"$@"`; danach haben die Positionsparameter wieder ihre alten Werte. `$0` bleibt der Name des Skripts.
|
||||
- `return [n]` beendet die Funktion mit dem Status `n` (ohne `n`: der Status des letzten Befehls). Ohne `return` ist der Status der des letzten Befehls.
|
||||
- Funktionen laufen in der Shell selbst: Variablen, die sie setzen, und `cd` gelten danach weiter. `local name[=wert]` macht eine Variable lokal, sie bekommt beim Verlassen der Funktion ihren alten Wert zurück (Funktionen, die von dort aufgerufen werden, sehen den lokalen Wert).
|
||||
- `name=wert funktion` setzt die Variable nur während des Aufrufs.
|
||||
- In einer Pipeline, im Hintergrund (`funktion &`) und in `$(...)` läuft eine Funktion in einer Subshell, Änderungen an Variablen gehen dort also verloren (wie in `sh`). Die Subshell kennt alle Funktionen.
|
||||
- Eine Funktion hat Vorrang vor Built-ins und Programmen gleichen Namens. Weil es noch kein `command` gibt, kann eine Funktion `ls` das Programm `ls` aber nicht aufrufen. Mit `\ls` umgeht man nur Aliase. Besser ist ein anderer Name, z. B. `ll() { ls -l "$@"; }`.
|
||||
- `unset -f name` entfernt eine Funktion. Rekursion ist erlaubt, aber nur bis zu einer Tiefe von 1000.
|
||||
- Namen dürfen aus Buchstaben, Ziffern, `_`, `-` und `.` bestehen (nicht mit einer Ziffer oder `-` beginnend). Funktionen werden auch mit Tab vervollständigt.
|
||||
|
||||
### Positionsparameter
|
||||
|
||||
| Parameter | Bedeutung |
|
||||
|--------------------|------------------------------------------------------------------|
|
||||
| `$0` | Name des Skripts (bzw. `name` bei `gosh -c befehl name`) |
|
||||
| `$1` … `$9`, `${10}` | die Argumente |
|
||||
| `$#` | Anzahl der Argumente |
|
||||
| `"$@"` | alle Argumente, jedes als eigenes Wort |
|
||||
| `"$*"` | alle Argumente als ein Wort, durch Leerzeichen getrennt |
|
||||
| `$$` | Prozess-ID der Shell |
|
||||
|
||||
```bash
|
||||
#!/usr/bin/gosh
|
||||
# aufruf: skript.gosh [-v] datei ...
|
||||
if [ $# -eq 0 ]; then
|
||||
echo "usage: $0 [-v] datei ..." >&2
|
||||
exit 2
|
||||
fi
|
||||
verbose=no
|
||||
case $1 in
|
||||
-v) verbose=yes; shift ;;
|
||||
esac
|
||||
for f in "$@"; do
|
||||
test $verbose = yes && echo "verarbeite $f"
|
||||
wc -l "$f"
|
||||
done
|
||||
```
|
||||
|
||||
- Gesetzt werden sie von `gosh skript a b`, `gosh -c befehl name a b`, beim Aufruf einer Funktion, mit `source datei a b` (nur während die Datei läuft) und mit `set -- a b c`.
|
||||
- `shift [n]` entfernt die ersten `n` (Standard: 1) Parameter, `$2` wird zu `$1` usw.
|
||||
- Wie bei Variablen ist ein nicht gesetzter Parameter ein Fehler: `$1` ohne Argumente meldet `1: unbound variable`. Für optionale Argumente `${1:-}` bzw. `${1:-standard}` verwenden oder vorher `$#` prüfen.
|
||||
- `"$@"` ohne Argumente ergibt kein Wort (auch nicht das leere). Ohne Anführungszeichen verhalten sich `$@` und `$*` wie `"$@"`, da gosh Werte nie an Leerzeichen teilt.
|
||||
|
||||
### read
|
||||
|
||||
`read` liest eine Zeile von stdin und verteilt sie auf Variablen:
|
||||
|
||||
```bash
|
||||
read -p "Name? " name # Eingabe vom Terminal mit Prompt
|
||||
read vorname nachname < name.txt # erste Zeile einer Datei
|
||||
read -r zeile # Backslashes nicht auswerten
|
||||
while read -r zeile; do echo "$zeile"; done # in einem Skript: alle Zeilen von stdin
|
||||
```
|
||||
|
||||
- `read name1 name2 …` teilt die Zeile an den Zeichen von `$IFS` (Standard: Leerzeichen, Tab, Zeilenumbruch). Jede Variable bekommt ein Feld, die letzte den Rest der Zeile. Bei zu wenigen Feldern werden die übrigen Variablen leer. Leerzeichen am Anfang und Ende werden entfernt. Andere `IFS`-Zeichen trennen genau ein Feld (`IFS=:` macht aus `a::b` die Felder `a`, ``, `b`).
|
||||
- Ohne Namen landet die ganze Zeile unverändert in `$REPLY`.
|
||||
- Ohne `-r` maskiert `\` das nächste Zeichen (`a\ b` bleibt ein Feld), und ein `\` am Zeilenende setzt die Zeile fort. `-p prompt` gibt den Prompt auf stderr aus, wenn stdin ein Terminal ist.
|
||||
- Der Status ist 0, oder 1 am Ende der Eingabe (die Variablen werden trotzdem mit dem Rest gesetzt). So endet `while read …` nach der letzten Zeile.
|
||||
- `read` liest Byte für Byte und damit nie mehr als eine Zeile, den Rest bekommen die nächsten Befehle. Ctrl+C bricht `read` in der interaktiven Shell ab (Status 130).
|
||||
- `read` verändert die Shell und lässt sich deshalb nicht als einfacher Befehl in einer Pipeline verwenden (`echo a | read x`, in `sh` wirkungslos). Umleitungen funktionieren: `read x < datei`, `read x <<< "$text"`, `while read l; do …; done < datei`. In einer Schleife in einer Pipe (`… | while read l; do …; done`) geht es auch, da die ganze Schleife in einer Subshell läuft.
|
||||
|
||||
### Variablen
|
||||
|
||||
```bash
|
||||
name=wert # Variable setzen (wie set name=wert)
|
||||
a=1 b=2 # mehrere auf einmal
|
||||
gruss="Hallo Welt" # Leerzeichen im Wert brauchen Anführungszeichen
|
||||
heute=$(date +%F) # Ausgabe eines Befehls
|
||||
PATH=~/bin:$PATH # ~ wird auch nach = und : ersetzt
|
||||
LANG=C sort datei # nur für diesen einen Befehl
|
||||
unset name # Variable entfernen
|
||||
echo $name ${name:-standard}
|
||||
```
|
||||
|
||||
- Eine Zuweisung ist ein Wort `name=wert` am Anfang eines Befehls, bei dem `name` und `=` ohne Anführungszeichen stehen und `name` aus Buchstaben, Ziffern und `_` besteht (nicht mit einer Ziffer beginnend). `"x=1"`, `x\=1` und `echo x=1` sind keine Zuweisungen.
|
||||
- Steht danach kein Befehl, wird die Variable in der Shell gesetzt. Wie bei `set` und `export` sind in gosh alle Variablen auch für gestartete Programme sichtbar (es gibt keine reinen Shell-Variablen).
|
||||
- Steht ein Befehl danach (`LANG=C sort datei`), gilt die Zuweisung nur für diesen Befehl, die Shell behält den alten Wert.
|
||||
- Der Wert wird nicht in Wörter geteilt und nicht als Wildcard oder `{a,b}` expandiert: `x=$(ls)` speichert die ganze Ausgabe, `x=*.go` speichert `*.go`. Variablen, `$(...)` und `~` (am Anfang, nach `=` und nach `:`) werden ersetzt.
|
||||
- `$?` ist nach einer Zuweisung der Status des letzten `$(...)` darin, sonst 0.
|
||||
- Variablen in den Argumenten werden ersetzt, bevor die Zuweisung davor gilt: `x=1 echo $x` gibt nicht `1` aus, sondern meldet `x: unbound variable` (wenn `x` vorher nicht gesetzt war).
|
||||
- In einer Pipeline (`x=1 | cat`) ändert eine Zuweisung die Shell nicht.
|
||||
|
||||
### Befehlsersetzung
|
||||
|
||||
@@ -190,7 +380,7 @@ $ vim $(grep -l TODO *.go)
|
||||
$ echo "Dateien: $(ls | wc -l)"
|
||||
```
|
||||
|
||||
- Der Befehl läuft in einer eigenen Subshell (einem neuen gosh-Prozess): `cd`, `set` oder `export` darin ändern die laufende Shell nicht. Er darf alles enthalten, was gosh kann (Pipes, `;`, `&&`, Umleitungen, verschachtelte `$(...)`), und liest von der gleichen Eingabe, Fehlermeldungen gehen auf stderr.
|
||||
- Der Befehl läuft in einer eigenen Subshell (einem neuen gosh-Prozess): `cd`, `set` oder `export` darin ändern die laufende Shell nicht. Die Subshell kennt die Funktionen und Positionsparameter der Shell. Er darf alles enthalten, was gosh kann (Pipes, `;`, `&&`, Umleitungen, verschachtelte `$(...)`), und liest von der gleichen Eingabe, Fehlermeldungen gehen auf stderr.
|
||||
- Abschließende Zeilenumbrüche der Ausgabe werden entfernt.
|
||||
- Ohne Anführungszeichen wird die Ausgabe an Leerzeichen, Tabs und Zeilenumbrüchen in mehrere Wörter geteilt, `"$(befehl)"` bleibt ein einziges Wort (mit den Zeilenumbrüchen darin).
|
||||
- Anders als in `sh` werden Wildcards in der Ausgabe nicht expandiert, und Zeichen wie `;` oder `|` darin sind normaler Text: Die Ausgabe ist immer nur Daten.
|
||||
@@ -273,7 +463,7 @@ $ ls -d */ # nur Verzeichnisse
|
||||
- Versteckte Dateien (mit `.` am Anfang) werden nur gefunden, wenn das Muster selbst mit `.` beginnt: `*` findet `.bashrc` nicht, `.*rc` schon.
|
||||
- Passt keine Datei, bleibt das Wort unverändert stehen (wie in `sh`), `ls *.xyz` meldet dann also `ls` den Fehler.
|
||||
- In Anführungszeichen oder mit `\` davor sind die Zeichen normale Zeichen: `echo "*"`, `echo '*.go'`, `echo \*`.
|
||||
- Werte von Variablen werden nicht als Muster behandelt (anders als in `sh`): Nach `set P=*.go` gibt `echo $P` wörtlich `*.go` aus. So kann ein Variablenwert nie unbemerkt auf viele Dateien passen. `echo $DIR/*.go` funktioniert dagegen, weil das `*` direkt in der Zeile steht.
|
||||
- Werte von Variablen werden nicht als Muster behandelt (anders als in `sh`): Nach `P='*.go'` gibt `echo $P` wörtlich `*.go` aus. So kann ein Variablenwert nie unbemerkt auf viele Dateien passen. `echo $DIR/*.go` funktioniert dagegen, weil das `*` direkt in der Zeile steht.
|
||||
- Bei einer Umleitung muss das Muster genau eine Datei treffen (`> *.log`), sonst meldet gosh `ambiguous redirect`.
|
||||
|
||||
### Pipes und Umleitungen
|
||||
@@ -294,13 +484,47 @@ $ grep -c error < build.log
|
||||
| `2>&1` | stderr dorthin, wohin stdout gerade geht |
|
||||
| `>&2` | stdout dorthin, wohin stderr gerade geht |
|
||||
| `&> datei` | stdout und stderr in `datei` (`&>>` hängt an) |
|
||||
| `<<EOF` | Here-Doc: die folgenden Zeilen bis `EOF` sind stdin |
|
||||
| `<<< wort` | Here-String: `wort` (und ein Zeilenumbruch) ist stdin |
|
||||
| `> datei` | ohne Befehl: legt `datei` an bzw. leert sie |
|
||||
|
||||
- Umleitungen werden von links nach rechts ausgewertet: `befehl > log 2>&1` schreibt beides in `log`, `befehl 2>&1 > log` schickt stderr dorthin, wo stdout vorher hinging (z. B. in eine Pipe).
|
||||
- Unterstützt werden die Dateideskriptoren 0, 1 und 2. Vor `>` und `<` zählt nur eine Zahl ohne Anführungszeichen als Deskriptor (`2>f`, aber nicht `x2>f` oder `"2">f`).
|
||||
- Operatoren in Anführungszeichen oder mit `\` davor sind normale Zeichen: `echo "a|b" 'c>d' e\>f`.
|
||||
- Der Exit-Status einer Pipeline ist der des letzten Befehls. Beendet sich ein Befehl am Ende (z. B. `head`), bekommt der schreibende Befehl davor `SIGPIPE`, `yes | head -1` endet also sofort.
|
||||
- Die Built-ins `pwd` und `help` lassen sich umleiten und in Pipes verwenden (`help | less`). `cd`, `set`, `export`, `exit` und `quit` verändern die Shell selbst und sind in einer Pipeline nicht erlaubt.
|
||||
- Die Built-ins `pwd` und `help` lassen sich umleiten und in Pipes verwenden (`help | less`). `cd`, `set`, `export`, `exit` und `quit` verändern die Shell selbst und sind in einer Pipeline nicht erlaubt. Umleitungen von `source datei > log` gelten für alle Befehle der Datei.
|
||||
- Zu Kontrollstrukturen mit Umleitungen und in Pipes siehe oben.
|
||||
|
||||
### Here-Docs und Here-Strings
|
||||
|
||||
```bash
|
||||
cat <<EOF > config.ini
|
||||
[server]
|
||||
host = $HOSTNAME
|
||||
started = $(date +%F)
|
||||
EOF
|
||||
|
||||
cat <<'EOF' > script.sh # 'EOF': nichts wird ersetzt
|
||||
echo "$HOME bleibt wörtlich stehen"
|
||||
EOF
|
||||
|
||||
if true; then
|
||||
cat <<-EOF # <<-: Tabs am Zeilenanfang werden entfernt
|
||||
eingerückt
|
||||
EOF
|
||||
fi
|
||||
|
||||
grep -c x <<< "$text" # Here-String
|
||||
read a b <<< "1 2"
|
||||
```
|
||||
|
||||
- Nach `<<WORT` folgen ab der nächsten Zeile die Eingabezeilen, bis zu einer Zeile, die genau `WORT` ist. In der interaktiven Shell zeigt gosh dafür den Fortsetzungs-Prompt `> `.
|
||||
- Ohne Anführungszeichen am Wort werden `$VAR`, `${VAR}`, `$(…)` und `\` vor `$`, `` ` ``, `\` und dem Zeilenende ersetzt (wie in `"…"`, nur dass `"` ein normales Zeichen ist). Wildcards, `~` und `{a,b}` werden nicht ersetzt. Ist das Wort ganz oder teilweise in Anführungszeichen (`'EOF'`, `"EOF"`, `\EOF`), wird nichts ersetzt.
|
||||
- `<<-WORT` entfernt Tabs (keine Leerzeichen) am Anfang jeder Zeile und der Endzeile, damit sich Here-Docs in Skripten einrücken lassen.
|
||||
- Mehrere Here-Docs in einer Zeile (`cat <<A; cat <<B`) folgen nacheinander. Here-Docs gehen auch an Funktionen, Schleifen (`done <<EOF`) und in Pipes.
|
||||
- `<<< wort` übergibt `wort` mit einem Zeilenumbruch als Eingabe. Das Wort wird wie ein Argument expandiert (Variablen, `$(…)`), aber nicht als Wildcard.
|
||||
- Die Eingabe steht in einer temporären Datei, die sofort wieder gelöscht wird, deshalb sind auch große Here-Docs kein Problem.
|
||||
- Ein Here-Doc in einer Befehlsersetzung (`x=$(cat <<EOF … EOF)`) funktioniert, solange der Text darin keine unpaarigen Anführungszeichen wie `it's` enthält.
|
||||
|
||||
### Aliase
|
||||
|
||||
@@ -482,4 +706,4 @@ git push origin v0.1.0
|
||||
goreleaser release --clean
|
||||
```
|
||||
|
||||
Das Paket installiert `/usr/bin/gosh` und trägt die Shell in `/etc/shells` ein, sodass sie mit `chsh -s /usr/bin/gosh` gesetzt werden kann.
|
||||
Das Paket installiert `/usr/bin/gosh` und die Man-Page `gosh(1)` (`man gosh`, Quelle: `packaging/man/gosh.1`, lokal ansehen mit `man ./packaging/man/gosh.1`) und trägt die Shell in `/etc/shells` ein, sodass sie mit `chsh -s /usr/bin/gosh` gesetzt werden kann.
|
||||
+109
@@ -0,0 +1,109 @@
|
||||
package main
|
||||
|
||||
import (
|
||||
"os"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func TestTokenize_Assignments(t *testing.T) {
|
||||
t.Setenv("HOME", "/home/u")
|
||||
tests := []struct {
|
||||
input string
|
||||
word string
|
||||
assign bool
|
||||
}{
|
||||
{"x=1", "x=1", true},
|
||||
{"_a1=", "_a1=", true},
|
||||
{`x="a b"`, "x=a b", true},
|
||||
{"x=a=b", "x=a=b", true},
|
||||
{"P=~/bin:~/go/bin", "P=/home/u/bin:/home/u/go/bin", true},
|
||||
{"x=a~b", "x=a~b", true},
|
||||
{"x=~", "x=/home/u", true},
|
||||
// Not an assignment: quoted or escaped name or =, invalid name
|
||||
{`"x=1"`, "x=1", false},
|
||||
{`x"=1"`, "x=1", false},
|
||||
{`x\=1`, "x=1", false},
|
||||
{"1x=2", "1x=2", false},
|
||||
{"=x", "=x", false},
|
||||
{"a-b=1", "a-b=1", false},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
tokens, err := tokenize(tc.input)
|
||||
if err != nil || len(tokens) != 1 {
|
||||
t.Errorf("tokenize(%q) = %+v, %v", tc.input, tokens, err)
|
||||
continue
|
||||
}
|
||||
if tokens[0].word != tc.word || tokens[0].assign != tc.assign {
|
||||
t.Errorf("tokenize(%q) = %q (assign %v), want %q (assign %v)",
|
||||
tc.input, tokens[0].word, tokens[0].assign, tc.word, tc.assign)
|
||||
}
|
||||
}
|
||||
|
||||
// The output of $(...) is not split in an assignment
|
||||
tokens, _ := tokenize("x=$(echo a b) y")
|
||||
if len(tokens) != 2 || tokens[0].word != "x=a b" || !tokens[0].assign {
|
||||
t.Errorf("x=$(echo a b): %+v", tokens)
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_Assignments(t *testing.T) {
|
||||
for _, name := range []string{"GOSH_A", "GOSH_B", "GOSH_C"} {
|
||||
os.Unsetenv(name)
|
||||
defer os.Unsetenv(name)
|
||||
}
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"GOSH_A=1; echo $GOSH_A > out", "1\n"},
|
||||
{"GOSH_A=1 GOSH_B=2; echo $GOSH_A$GOSH_B > out", "12\n"},
|
||||
{`GOSH_A="a b"; echo "$GOSH_A" > out`, "a b\n"},
|
||||
{"GOSH_A=$(printf 'a b\\nc'); echo \"$GOSH_A\" > out", "a b\nc\n"},
|
||||
// No wildcard or brace expansion in the value
|
||||
{"touch x.go; GOSH_A=*.go; echo \"$GOSH_A\" > out", "*.go\n"},
|
||||
{"GOSH_A={a,b}; echo $GOSH_A > out", "{a,b}\n"},
|
||||
// ... but as an argument, assignment-like words are normal words
|
||||
{"echo GOSH_A={a,b} > out", "GOSH_A=a GOSH_A=b\n"},
|
||||
// Before a command, only in its environment
|
||||
{"GOSH_C=temp sh -c 'echo $GOSH_C' > out; echo ${GOSH_C:-unset} >> out", "temp\nunset\n"},
|
||||
{"GOSH_A=old; GOSH_A=new sh -c 'echo $GOSH_A' > out; echo $GOSH_A >> out", "new\nold\n"},
|
||||
// ... and before a builtin only while it runs
|
||||
{"GOSH_C=temp pwd > /dev/null; echo ${GOSH_C:-unset} > out", "unset\n"},
|
||||
// In a pipeline or with a command they do not change the shell
|
||||
{"GOSH_C=x | cat; echo ${GOSH_C:-unset} > out", "unset\n"},
|
||||
// Redirections are applied
|
||||
{"GOSH_A=r > out", ""},
|
||||
// In loops
|
||||
{"for i in 1 2 3; do GOSH_A=$i; done; echo $GOSH_A > out", "3\n"},
|
||||
{"GOSH_B=0; while [ $GOSH_B -lt 3 ]; do echo $GOSH_B >> out; GOSH_B=$(expr $GOSH_B + 1); done", "0\n1\n2\n"},
|
||||
// Not assignments
|
||||
{`echo "GOSH_A=1" GOSH_B=2 > out`, "GOSH_A=1 GOSH_B=2\n"},
|
||||
// unset
|
||||
{"GOSH_A=1; unset GOSH_A; echo ${GOSH_A:-gone} > out", "gone\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
|
||||
// The status of an assignment is the one of its last $(...)
|
||||
for input, want := range map[string]int{
|
||||
"GOSH_A=1": 0,
|
||||
"GOSH_A=$(false)": 1,
|
||||
"GOSH_A=$(sh -c 'exit 3')": 3,
|
||||
"GOSH_A=$(false) GOSH_B=$(true)": 0,
|
||||
} {
|
||||
runIn(t, input)
|
||||
if lastStatus != want {
|
||||
t.Errorf("%q: $? = %d, want %d", input, lastStatus, want)
|
||||
}
|
||||
}
|
||||
|
||||
if err := execInput("unset 1x"); err == nil || err.Error() != "unset: `1x': not a valid identifier" {
|
||||
t.Errorf("unset 1x: %v", err)
|
||||
}
|
||||
if err := execInput(`"GOSH_A=1"`); err == nil || exitStatus(err) != 127 {
|
||||
t.Errorf(`"GOSH_A=1" must be a command: %v`, err)
|
||||
}
|
||||
}
|
||||
@@ -22,6 +22,7 @@ func expandBraceWords(input string) (string, error) {
|
||||
var (
|
||||
out strings.Builder
|
||||
afterRedirect bool // the next word is the target of a redirection
|
||||
commandStart = true
|
||||
)
|
||||
|
||||
for i := 0; i < len(input); {
|
||||
@@ -33,6 +34,8 @@ func expandBraceWords(input string) (string, error) {
|
||||
case strings.IndexByte(";&|<>", ch) >= 0:
|
||||
if ch == '<' || ch == '>' {
|
||||
afterRedirect = true
|
||||
} else {
|
||||
commandStart = true
|
||||
}
|
||||
out.WriteByte(ch)
|
||||
i++
|
||||
@@ -42,6 +45,16 @@ func expandBraceWords(input string) (string, error) {
|
||||
return out.String(), nil
|
||||
default:
|
||||
end := wordEnd(input, i)
|
||||
if commandStart && !afterRedirect && isAssignment(input[i:end]) {
|
||||
// name=value before the command: no brace expansion, like
|
||||
// in bash
|
||||
out.WriteString(input[i:end])
|
||||
i = end
|
||||
continue
|
||||
}
|
||||
if !afterRedirect {
|
||||
commandStart = false
|
||||
}
|
||||
words, err := expandBraces(input[i:end])
|
||||
if err != nil {
|
||||
return "", err
|
||||
@@ -57,6 +70,12 @@ func expandBraceWords(input string) (string, error) {
|
||||
return out.String(), nil
|
||||
}
|
||||
|
||||
// isAssignment reports whether a word starts with name= (unquoted).
|
||||
func isAssignment(word string) bool {
|
||||
name, _, ok := strings.Cut(word, "=")
|
||||
return ok && isVarName(name)
|
||||
}
|
||||
|
||||
// wordEnd returns the end of the word starting at i: the next unquoted blank
|
||||
// or operator character.
|
||||
func wordEnd(s string, i int) int {
|
||||
|
||||
@@ -0,0 +1,274 @@
|
||||
package main
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"os"
|
||||
"reflect"
|
||||
"strings"
|
||||
"testing"
|
||||
"time"
|
||||
)
|
||||
|
||||
func TestExec_CompoundRedirections(t *testing.T) {
|
||||
resetShell(t)
|
||||
for _, name := range []string{"GOSH_A", "GOSH_N"} {
|
||||
os.Unsetenv(name)
|
||||
defer os.Unsetenv(name)
|
||||
}
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"if true; then echo yes; fi > out", "yes\n"},
|
||||
{"for x in a b; do echo $x; done > out", "a\nb\n"},
|
||||
{"for x in a b; do echo $x; done >> out; echo c >> out", "a\nb\nc\n"},
|
||||
{"{ echo out; echo err >&2; } > out 2>&1", "out\nerr\n"},
|
||||
{"{ echo err >&2; } 2> out", "err\n"},
|
||||
{"case x in x) echo case;; esac > out", "case\n"},
|
||||
// The redirections apply to all commands, also nested ones
|
||||
{"{ echo a; { echo b; }; } > out", "a\nb\n"},
|
||||
{"{ echo a; echo b > other; echo c; } > out", "a\nc\n"},
|
||||
{"f() { echo from-f; }; { f; } > out", "from-f\n"},
|
||||
// Reading a file line by line in the shell itself
|
||||
{"printf 'l1\\nl2 x\\n' > in; while read -r l; do echo \"<$l>\" >> out; done < in", "<l1>\n<l2 x>\n"},
|
||||
{"printf 'a b\\nc d\\n' > in; while read x y; do echo $y$x >> out; done < in", "ba\ndc\n"},
|
||||
{"printf '1\\n2\\n3\\n' > in; GOSH_N=0; while read l; do GOSH_N=$(expr $GOSH_N + $l); done < in; echo $GOSH_N > out", "6\n"},
|
||||
// ... with the loop's variables changed in the shell
|
||||
{"printf 'v\\n' > in; while read GOSH_A; do :; done < in; echo ${GOSH_A:-empty} > out", "empty\n"},
|
||||
{"printf 'v\\n' > in; { read GOSH_A; } < in; echo $GOSH_A > out", "v\n"},
|
||||
// Redirections are expanded
|
||||
{"GOSH_A=out; { echo var; } > $GOSH_A", "var\n"},
|
||||
// Files are closed and stdout is restored afterwards
|
||||
{"{ echo a; } > out; echo b >> out", "a\nb\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
if ioOverride != [3]*os.File{} {
|
||||
t.Fatalf("%q: ioOverride not restored", tc.input)
|
||||
}
|
||||
}
|
||||
|
||||
for input, want := range map[string]string{
|
||||
"{ :; } < gosh-no-such-file": "gosh-no-such-file: no such file or directory",
|
||||
"{ :; } > {a,b}": "{a,b}: ambiguous redirect",
|
||||
} {
|
||||
if err := runInErr(t, input); err == nil || err.Error() != want {
|
||||
t.Errorf("%q: err = %v, want %q", input, err, want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// runInErr runs input in a temporary directory and returns its error.
|
||||
func runInErr(t *testing.T, input string) error {
|
||||
t.Helper()
|
||||
origDir, _ := os.Getwd()
|
||||
defer os.Chdir(origDir)
|
||||
os.Chdir(t.TempDir())
|
||||
return execInput(input)
|
||||
}
|
||||
|
||||
func TestExec_CompoundPipelines(t *testing.T) {
|
||||
resetShell(t)
|
||||
os.Unsetenv("GOSH_A")
|
||||
defer os.Unsetenv("GOSH_A")
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"for x in 3 1 2; do echo $x; done | sort > out", "1\n2\n3\n"},
|
||||
{"printf 'a b\\nc d\\n' | while read x y; do echo $y$x; done > out", "ba\ndc\n"},
|
||||
{"echo hi | { read l; echo got $l; } > out", "got hi\n"},
|
||||
{"if true; then echo yes; fi | tr a-z A-Z > out", "YES\n"},
|
||||
{"echo x | case y in y) cat;; esac | tr x X > out", "X\n"},
|
||||
{"for x in a b; do echo $x; done > /dev/null | cat > out", ""},
|
||||
{"{ echo b; echo a; } | sort | head -1 > out", "a\n"},
|
||||
// The parts of a pipeline run in subshells: the shell is not changed
|
||||
{"echo v | while read GOSH_A; do :; done; echo ${GOSH_A:-unset} > out", "unset\n"},
|
||||
// Functions and positional parameters are known in the subshell
|
||||
{"f() { echo f-$1; }; set -- p; for x in 1; do f $1; done | cat > out", "f-p\n"},
|
||||
// The status is the one of the last command
|
||||
{"echo | while read l; do false; done; echo $? > out", "1\n"},
|
||||
{"true | if false; then :; else sh -c 'exit 3'; fi; echo $? > out", "3\n"},
|
||||
{"for x in 1; do sh -c 'exit 4'; done | true; echo $? > out", "0\n"},
|
||||
{"! echo | while read l; do false; done; echo $? > out", "0\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_Subshells(t *testing.T) {
|
||||
resetShell(t)
|
||||
os.Unsetenv("GOSH_A")
|
||||
defer os.Unsetenv("GOSH_A")
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"(echo a; echo b) > out", "a\nb\n"},
|
||||
{"(echo sub) | tr a-z A-Z > out", "SUB\n"},
|
||||
// Changes stay in the subshell
|
||||
{"mkdir d; (cd d; pwd > ../in); cd d 2>/dev/null && echo still-outside > out", "still-outside\n"},
|
||||
{"GOSH_A=1; (GOSH_A=2; echo $GOSH_A > out); echo $GOSH_A >> out", "2\n1\n"},
|
||||
{"(exit 3); echo $? > out", "3\n"},
|
||||
{"(exit 3) || echo failed > out", "failed\n"},
|
||||
{"(f() { echo in-sub; }; f) > out; f 2>> out || echo no-f >> out", "in-sub\nno-f\n"},
|
||||
{"(echo a; (echo b)) > out", "a\nb\n"},
|
||||
{"( echo spaced ) > out", "spaced\n"},
|
||||
{"(\n echo multi\n echo line\n) > out", "multi\nline\n"},
|
||||
// The subshell knows the functions and positional parameters
|
||||
{"f() { echo f-$1; }; set -- p; (f $1) > out", "f-p\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_CompoundBackground(t *testing.T) {
|
||||
resetShell(t)
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"for x in a b; do echo $x; done > out & wait", "a\nb\n"},
|
||||
{"true && echo and > out & wait", "and\n"},
|
||||
{"false || echo or > out & wait", "or\n"},
|
||||
{"(echo sub > out) & wait", "sub\n"},
|
||||
{"{ echo group; } > out & wait", "group\n"},
|
||||
{"! false && echo negated > out & wait", "negated\n"},
|
||||
{"for x in 3 1; do echo $x; done | sort > out & wait", "1\n3\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
// The shell does not wait for a background loop
|
||||
start := time.Now()
|
||||
runIn(t, "for x in 1; do sleep 1; done & echo $? > out")
|
||||
if lastStatus != 0 || time.Since(start) > 500*time.Millisecond {
|
||||
t.Errorf("background loop: $? = %d after %v", lastStatus, time.Since(start))
|
||||
}
|
||||
execInput("wait")
|
||||
}
|
||||
|
||||
func TestExtractHeredocs(t *testing.T) {
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"cat <<EOF\nhello\nEOF\n", "cat <<<\"hello\"\n"},
|
||||
{"cat <<EOF\nhello\nEOF", "cat <<<\"hello\"\n"},
|
||||
{"cat << EOF\na\nb\nEOF\necho x\n", "cat <<<\"a\nb\"\necho x\n"},
|
||||
{"cat <<'EOF'\n$x \"q\" it's\nEOF\n", "cat <<<'$x \"q\" it'\\''s'\n"},
|
||||
{"cat <<\"EOF\"\n$x\nEOF\n", "cat <<<'$x'\n"},
|
||||
{"cat <<\\EOF\n$x\nEOF\n", "cat <<<'$x'\n"},
|
||||
{"cat <<E\"O\"F\n$x\nEOF\n", "cat <<<'$x'\n"},
|
||||
{"cat <<EOF\n\"q\" \\\" \\$x \\a\nEOF\n", "cat <<<\"\\\"q\\\" \\\\\\\" \\$x \\\\a\"\n"},
|
||||
{"cat <<EOF\n$(echo \"a\")\nEOF\n", "cat <<<\"$(echo \"a\")\"\n"},
|
||||
{"cat <<-EOF\n\t\ttabs\n\tEOF\n", "cat <<<\"tabs\"\n"},
|
||||
{"cat <<EOF\nEOF\n", "cat </dev/null\n"},
|
||||
{"cat <<A; cat <<B\na\nA\nb\nB\n", "cat <<<\"a\"; cat <<<\"b\"\n"},
|
||||
{"cat <<EOF | sort\nb\nEOF\n", "cat <<<\"b\" | sort\n"},
|
||||
// The delimiter must be the whole line
|
||||
{"cat <<EOF\n EOF\nEOFX\nEOF\n", "cat <<<\" EOF\nEOFX\"\n"},
|
||||
// Not here-documents
|
||||
{"echo '<<EOF'\n", "echo '<<EOF'\n"},
|
||||
{"echo \"<<EOF\"\n", "echo \"<<EOF\"\n"},
|
||||
{"echo \\<<x\n", "echo \\<<x\n"},
|
||||
{"echo # <<EOF\n", "echo # <<EOF\n"},
|
||||
{"cat <<<word\n", "cat <<<word\n"},
|
||||
{"echo $(echo a <<<b)\n", "echo $(echo a <<<b)\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
got, err := extractHeredocs(tc.input)
|
||||
if err != nil {
|
||||
t.Errorf("%q: %v", tc.input, err)
|
||||
continue
|
||||
}
|
||||
if got != tc.want {
|
||||
t.Errorf("%q:\n got %q\nwant %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
|
||||
for _, input := range []string{"cat <<EOF", "cat <<EOF\n", "cat <<EOF\nbody\n", "cat <<'EOF\n"} {
|
||||
if _, err := extractHeredocs(input); !errors.Is(err, errIncomplete) {
|
||||
t.Errorf("%q: err = %v, want incomplete", input, err)
|
||||
}
|
||||
}
|
||||
for _, input := range []string{"cat <<\n", "cat << ;\n"} {
|
||||
if _, err := extractHeredocs(input); err == nil || errors.Is(err, errIncomplete) {
|
||||
t.Errorf("%q: err = %v, want syntax error", input, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_Heredocs(t *testing.T) {
|
||||
resetShell(t)
|
||||
t.Setenv("GOSH_A", "value")
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"cat <<EOF > out\nhello\nworld\nEOF", "hello\nworld\n"},
|
||||
{"cat <<EOF > out\n$GOSH_A ${GOSH_A} $(echo sub) \\$GOSH_A\nEOF", "value value sub $GOSH_A\n"},
|
||||
{"cat <<'EOF' > out\n$GOSH_A $(echo sub)\nEOF", "$GOSH_A $(echo sub)\n"},
|
||||
{"cat <<EOF > out\n\"quotes\" 'single' back\\slash\nEOF", "\"quotes\" 'single' back\\slash\n"},
|
||||
{"cat <<EOF > out\nline \\\ncontinued\nEOF", "line continued\n"},
|
||||
{"cat <<'EOF' > out\nline \\\nkept\nEOF", "line \\\nkept\n"},
|
||||
{"cat <<-EOF > out\n\tindented\n\t\tmore\n\tEOF", "indented\nmore\n"},
|
||||
{"cat <<EOF > out\n *.go {a,b} ~\nEOF", " *.go {a,b} ~\n"},
|
||||
{"cat <<EOF > out\nEOF", ""},
|
||||
{"cat <<EOF | tr a-z A-Z > out\npiped\nEOF", "PIPED\n"},
|
||||
{"cat > out <<EOF\nredirect first\nEOF", "redirect first\n"},
|
||||
{"cat <<A > out; cat <<B >> out\na\nA\nb\nB", "a\nb\n"},
|
||||
{"while read l; do echo \"<$l>\" >> out; done <<EOF\none\ntwo\nEOF", "<one>\n<two>\n"},
|
||||
{"f() { cat; }; f <<EOF > out\nto f\nEOF", "to f\n"},
|
||||
{"set -- a 'b c'; cat <<EOF > out\n$# $1 $@\nEOF", "2 a a b c\n"},
|
||||
{"for x in 1 2; do\n cat <<EOF >> out\nx=$x\nEOF\ndone", "x=1\nx=2\n"},
|
||||
{"echo \"$(cat <<EOF\nin subst\nEOF\n)\" > out", "in subst\n"},
|
||||
// Here-strings
|
||||
{"cat <<<word > out", "word\n"},
|
||||
{"cat <<< \"two words $GOSH_A\" > out", "two words value\n"},
|
||||
{"cat <<<'*.go' > out", "*.go\n"},
|
||||
{"read x y <<<'a b c'; echo $y > out", "b c\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// TestRunScript_Heredoc checks that a script reads a here-document and
|
||||
// continues after it, with correct line numbers in error messages.
|
||||
func TestRunScript_Heredoc(t *testing.T) {
|
||||
resetShell(t)
|
||||
got := runIn(t, `printf 'cat <<EOF > out\nbody\nEOF\necho after >> out\n' > s; . ./s`)
|
||||
if got != "body\nafter\n" {
|
||||
t.Errorf("script with here-document: out = %q", got)
|
||||
}
|
||||
got = runIn(t, `printf 'cat <<EOF\nbody\n' > s; . ./s 2> out`)
|
||||
if !strings.Contains(got, "s:1: syntax error: unexpected end of file") {
|
||||
t.Errorf("unterminated here-document: %q", got)
|
||||
}
|
||||
}
|
||||
|
||||
// TestTokenize_UTF8 checks that non-ASCII characters survive quoting and
|
||||
// escaping (each byte used to be converted to a rune of its own).
|
||||
func TestTokenize_UTF8(t *testing.T) {
|
||||
got, err := splitWords(`echo 'wörtlich' "für" über \ä 'a'"ö"`)
|
||||
want := []string{"echo", "wörtlich", "für", "über", "ä", "aö"}
|
||||
if err != nil || !reflect.DeepEqual(got, want) {
|
||||
t.Errorf("got %q, %v, want %q", got, err, want)
|
||||
}
|
||||
if got := runIn(t, "cat <<'EOF' > out\nGrüße\nEOF"); got != "Grüße\n" {
|
||||
t.Errorf("here-document: %q", got)
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,231 @@
|
||||
package main
|
||||
|
||||
// Functions and positional parameters. A function runs in the shell itself
|
||||
// (it can change variables and the directory), with its arguments as the
|
||||
// positional parameters $1, $2, ... In a pipeline, in the background and in
|
||||
// $(...) it runs in a subshell, which gets the definitions of all functions.
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"fmt"
|
||||
"os"
|
||||
"slices"
|
||||
"sort"
|
||||
"strconv"
|
||||
"strings"
|
||||
)
|
||||
|
||||
// funcDef is a function defined with name() { ...; }.
|
||||
type funcDef struct {
|
||||
name string
|
||||
body node
|
||||
text string // the source of the definition, passed to subshells
|
||||
}
|
||||
|
||||
var (
|
||||
functions = map[string]*funcDef{}
|
||||
|
||||
// scriptName is $0: the script, the name given after gosh -c command,
|
||||
// or the name gosh was started with.
|
||||
scriptName = "gosh"
|
||||
// positional are the positional parameters $1, $2, ...
|
||||
positional []string
|
||||
|
||||
// funcDepth is the number of functions that are currently running.
|
||||
funcDepth int
|
||||
// localFrames holds, for every running function, the previous values
|
||||
// of the variables it declared with local.
|
||||
localFrames []map[string]savedVar
|
||||
|
||||
// ioOverride replaces stdin, stdout and stderr of the shell while a
|
||||
// function with redirections runs (f > file), so that the commands in
|
||||
// it use the redirected files.
|
||||
ioOverride [3]*os.File
|
||||
)
|
||||
|
||||
// maxFuncDepth limits the nesting of function calls, so that endless
|
||||
// recursion ends with an error.
|
||||
const maxFuncDepth = 1000
|
||||
|
||||
type savedVar struct {
|
||||
value string
|
||||
ok bool
|
||||
}
|
||||
|
||||
// returnSignal is returned by the return builtin and ends the running
|
||||
// function or sourced file with the given status.
|
||||
type returnSignal struct {
|
||||
status int
|
||||
}
|
||||
|
||||
func (r returnSignal) Error() string { return "return" }
|
||||
|
||||
// stdio returns stdin (0), stdout (1) or stderr (2) of the shell, which are
|
||||
// redirected while a function with redirections runs.
|
||||
func stdio(fd int) *os.File {
|
||||
if f := ioOverride[fd]; f != nil {
|
||||
return f
|
||||
}
|
||||
return [3]*os.File{os.Stdin, os.Stdout, os.Stderr}[fd]
|
||||
}
|
||||
|
||||
// isFuncName reports whether name can be the name of a function: letters,
|
||||
// digits, _, - and ., not starting with a digit or -.
|
||||
func isFuncName(name string) bool {
|
||||
if name == "" || name[0] == '-' || name[0] >= '0' && name[0] <= '9' || terminators[name] || compoundStarts[name] {
|
||||
return false
|
||||
}
|
||||
for i := 0; i < len(name); i++ {
|
||||
if c := name[i]; !isVarNameByte(c, false) && c != '-' && c != '.' {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func defineFunction(def *funcDef) {
|
||||
functions[def.name] = def
|
||||
}
|
||||
|
||||
// functionNames returns the names of all functions, sorted.
|
||||
func functionNames() []string {
|
||||
names := make([]string, 0, len(functions))
|
||||
for name := range functions {
|
||||
names = append(names, name)
|
||||
}
|
||||
sort.Strings(names)
|
||||
return names
|
||||
}
|
||||
|
||||
// functionDefs returns the definitions of all functions as source text, to
|
||||
// run them in a subshell.
|
||||
func functionDefs() string {
|
||||
var b strings.Builder
|
||||
for _, name := range functionNames() {
|
||||
b.WriteString(functions[name].text)
|
||||
b.WriteByte('\n')
|
||||
}
|
||||
return b.String()
|
||||
}
|
||||
|
||||
// callFunction runs a function in the shell with args[1:] as positional
|
||||
// parameters, the files fds as stdin, stdout and stderr and the assignments
|
||||
// that came before the call set while it runs.
|
||||
func callFunction(fn *funcDef, args []string, fds [3]*os.File, assigns []string) error {
|
||||
if funcDepth >= maxFuncDepth {
|
||||
return fmt.Errorf("%s: maximum function nesting level exceeded (%d)", sanitize(fn.name), maxFuncDepth)
|
||||
}
|
||||
defer setTemporarily(assigns)()
|
||||
|
||||
savedIO, savedPositional, savedLoopDepth := ioOverride, positional, loopDepth
|
||||
ioOverride, positional, loopDepth = fds, slices.Clone(args[1:]), 0
|
||||
funcDepth++
|
||||
localFrames = append(localFrames, map[string]savedVar{})
|
||||
defer func() {
|
||||
// Restore the variables declared with local
|
||||
for name, v := range localFrames[len(localFrames)-1] {
|
||||
if v.ok {
|
||||
os.Setenv(name, v.value)
|
||||
} else {
|
||||
os.Unsetenv(name)
|
||||
}
|
||||
}
|
||||
localFrames = localFrames[:len(localFrames)-1]
|
||||
funcDepth--
|
||||
ioOverride, positional, loopDepth = savedIO, savedPositional, savedLoopDepth
|
||||
}()
|
||||
|
||||
err := fn.body.exec()
|
||||
var ret returnSignal
|
||||
if errors.As(err, &ret) {
|
||||
if ret.status == 0 {
|
||||
return nil
|
||||
}
|
||||
return statusError(ret.status)
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// lookupParam returns the value of a special or positional parameter ($?,
|
||||
// $#, $$, $0, $1, ..., $@ and $* joined with blanks) or of a variable.
|
||||
func lookupParam(name string) (string, bool) {
|
||||
switch {
|
||||
case name == "?":
|
||||
return strconv.Itoa(lastStatus), true
|
||||
case name == "#":
|
||||
return strconv.Itoa(len(positional)), true
|
||||
case name == "$":
|
||||
return strconv.Itoa(os.Getpid()), true
|
||||
case name == "@" || name == "*":
|
||||
return strings.Join(positional, " "), true
|
||||
case name == "0":
|
||||
return scriptName, true
|
||||
case isDigits(name):
|
||||
n, err := strconv.Atoi(name)
|
||||
if err != nil || n > len(positional) {
|
||||
return "", false
|
||||
}
|
||||
return positional[n-1], true
|
||||
}
|
||||
return os.LookupEnv(name)
|
||||
}
|
||||
|
||||
// builtinReturn implements return [n].
|
||||
func builtinReturn(args []string) error {
|
||||
if funcDepth == 0 && sourceDepth == 0 {
|
||||
return errors.New("return: can only `return' from a function or sourced script")
|
||||
}
|
||||
status := lastStatus
|
||||
if len(args) > 1 {
|
||||
n, err := strconv.Atoi(args[1])
|
||||
if err != nil {
|
||||
return fmt.Errorf("return: %s: numeric argument required", sanitize(args[1]))
|
||||
}
|
||||
status = n & 0xff
|
||||
}
|
||||
return returnSignal{status}
|
||||
}
|
||||
|
||||
// builtinLocal implements local name[=value] ...: the variables get their
|
||||
// previous values back when the function returns. Without a value the
|
||||
// variable is unset in the function.
|
||||
func builtinLocal(args []string) error {
|
||||
if funcDepth == 0 {
|
||||
return errors.New("local: can only be used in a function")
|
||||
}
|
||||
frame := localFrames[len(localFrames)-1]
|
||||
var err error
|
||||
for _, arg := range args[1:] {
|
||||
name, value, hasValue := strings.Cut(arg, "=")
|
||||
if !isVarName(name) {
|
||||
err = fmt.Errorf("local: `%s': not a valid identifier", sanitize(arg))
|
||||
continue
|
||||
}
|
||||
if _, saved := frame[name]; !saved {
|
||||
old, ok := os.LookupEnv(name)
|
||||
frame[name] = savedVar{old, ok}
|
||||
}
|
||||
if hasValue {
|
||||
os.Setenv(name, value)
|
||||
} else {
|
||||
os.Unsetenv(name)
|
||||
}
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// builtinShift implements shift [n].
|
||||
func builtinShift(args []string) error {
|
||||
n := 1
|
||||
if len(args) > 1 {
|
||||
var err error
|
||||
if n, err = strconv.Atoi(args[1]); err != nil || n < 0 {
|
||||
return fmt.Errorf("shift: %s: numeric argument required", sanitize(args[1]))
|
||||
}
|
||||
}
|
||||
if n > len(positional) {
|
||||
return fmt.Errorf("shift: %d: shift count out of range", n)
|
||||
}
|
||||
positional = positional[n:]
|
||||
return nil
|
||||
}
|
||||
+363
@@ -0,0 +1,363 @@
|
||||
package main
|
||||
|
||||
import (
|
||||
"os"
|
||||
"os/exec"
|
||||
"path/filepath"
|
||||
"reflect"
|
||||
"strings"
|
||||
"testing"
|
||||
)
|
||||
|
||||
// resetShell removes functions and positional parameters after a test.
|
||||
func resetShell(t *testing.T) {
|
||||
t.Helper()
|
||||
t.Cleanup(func() {
|
||||
functions = map[string]*funcDef{}
|
||||
positional, scriptName = nil, "gosh"
|
||||
})
|
||||
}
|
||||
|
||||
func TestTokenize_PositionalParameters(t *testing.T) {
|
||||
resetShell(t)
|
||||
scriptName, positional = "prog", []string{"a", "b c", ""}
|
||||
|
||||
tests := []struct {
|
||||
input string
|
||||
want []string
|
||||
}{
|
||||
{"echo $0 $1 $2", []string{"echo", "prog", "a", "b c"}},
|
||||
{"echo $# ${#}", []string{"echo", "3", "3"}},
|
||||
{`echo "$@"`, []string{"echo", "a", "b c", ""}},
|
||||
{`echo x"$@"y`, []string{"echo", "xa", "b c", "y"}},
|
||||
{`echo $@`, []string{"echo", "a", "b c", ""}},
|
||||
{`echo "$*"`, []string{"echo", "a b c "}},
|
||||
{`echo ${2}x $10`, []string{"echo", "b cx", "a0"}},
|
||||
{`echo ${4:-four}`, []string{"echo", "four"}},
|
||||
{`echo '$1' \$1`, []string{"echo", "$1", "$1"}},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
got, err := splitWords(tc.input)
|
||||
if err != nil {
|
||||
t.Errorf("%q: %v", tc.input, err)
|
||||
continue
|
||||
}
|
||||
if !reflect.DeepEqual(got, tc.want) {
|
||||
t.Errorf("%q: got %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
|
||||
// An unset positional parameter is an error, like an unset variable
|
||||
if _, err := splitWords("echo $4"); err == nil || !strings.Contains(err.Error(), "4: unbound variable") {
|
||||
t.Errorf("$4: err = %v", err)
|
||||
}
|
||||
|
||||
// "$@" without parameters is no word at all
|
||||
positional = nil
|
||||
for input, want := range map[string][]string{
|
||||
`echo "$@"`: {"echo"},
|
||||
`echo "$@" x`: {"echo", "x"},
|
||||
`echo "x$@"`: {"echo", "x"},
|
||||
`echo "$*"`: {"echo", ""},
|
||||
`echo $#`: {"echo", "0"},
|
||||
} {
|
||||
if got, _ := splitWords(input); !reflect.DeepEqual(got, want) {
|
||||
t.Errorf("%q without parameters: got %q, want %q", input, got, want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_Functions(t *testing.T) {
|
||||
resetShell(t)
|
||||
for _, name := range []string{"GOSH_A", "GOSH_L"} {
|
||||
os.Unsetenv(name)
|
||||
defer os.Unsetenv(name)
|
||||
}
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"f() { echo hi > out; }; f", "hi\n"},
|
||||
{"f () { echo $1-$2-$# >> out; }; f a b", "a-b-2\n"},
|
||||
{"f(){ echo braces >> out; }; f", "braces\n"},
|
||||
{"function f { echo keyword >> out; }; f", "keyword\n"},
|
||||
{"function f() { echo both >> out; }; f", "both\n"},
|
||||
{"f() {\n echo multi >> out\n echo line >> out\n}\nf", "multi\nline\n"},
|
||||
{"f()\n{\n echo next-line >> out\n}\nf", "next-line\n"},
|
||||
{"f() if true; then echo if-body >> out; fi; f", "if-body\n"},
|
||||
{`f() { for a in "$@"; do echo "<$a>" >> out; done; }; f x "y z"`, "<x>\n<y z>\n"},
|
||||
// The positional parameters are restored after the call
|
||||
{`set -- outer; f() { echo $1 >> out; }; f inner; echo $1 >> out`, "inner\nouter\n"},
|
||||
// Functions change the shell (variables, directory)
|
||||
{"f() { GOSH_A=set; }; f; echo $GOSH_A > out", "set\n"},
|
||||
// return
|
||||
{"f() { echo a >> out; return; echo b >> out; }; f", "a\n"},
|
||||
{"f() { return 3; }; f; echo $? > out", "3\n"},
|
||||
{"f() { false; return; }; f; echo $? > out", "1\n"},
|
||||
{"f() { for x in 1 2 3; do if [ $x = 2 ]; then return 7; fi; echo $x >> out; done; }; f; echo $? >> out", "1\n7\n"},
|
||||
{"f() { sh -c 'exit 4'; }; f; echo $? > out", "4\n"},
|
||||
// local
|
||||
{"GOSH_L=global; f() { local GOSH_L=local; echo $GOSH_L >> out; }; f; echo $GOSH_L >> out", "local\nglobal\n"},
|
||||
{"f() { local GOSH_L; GOSH_L=x; }; f; echo ${GOSH_L:-unset} > out", "unset\n"},
|
||||
{"f() { local GOSH_L=1; g; echo $GOSH_L >> out; }; g() { GOSH_L=2; }; f", "2\n"},
|
||||
// Assignments before a call apply only while it runs
|
||||
{"f() { echo $GOSH_A >> out; }; GOSH_A=temp f; echo ${GOSH_A:-unset} >> out", "temp\nunset\n"},
|
||||
// Redirections of a call apply to all commands in the function
|
||||
{"f() { echo one; echo two; }; f > out", "one\ntwo\n"},
|
||||
{"f() { echo err >&2; }; f 2> out", "err\n"},
|
||||
{"echo input > in; f() { cat; }; f < in > out", "input\n"},
|
||||
{"f() { echo nested > out; }; g() { f; }; g", "nested\n"},
|
||||
// Functions run before builtins and commands of the same name
|
||||
{"echo() { printf 'own\\n' > out; }; echo x; unset -f echo", "own\n"},
|
||||
{"f() { echo x > out; }; unset -f f; f", ""},
|
||||
// In pipelines, in the background and in $(...) they run in a subshell
|
||||
{"f() { echo piped; }; f | tr a-z A-Z > out", "PIPED\n"},
|
||||
{"f() { tr a-z A-Z; }; echo lower | f > out", "LOWER\n"},
|
||||
{"f() { echo bg > out; }; f & wait", "bg\n"},
|
||||
{`f() { echo "sub $1"; }; echo "$(f arg)" > out`, "sub arg\n"},
|
||||
{`f() { g; }; g() { echo g-in-sub; }; echo $(f) > out`, "g-in-sub\n"},
|
||||
{`set -- p1; echo "$(echo $1)" > out`, "p1\n"},
|
||||
{"f() { GOSH_A=changed; }; f | cat; echo ${GOSH_A:-unchanged} > out", "unchanged\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
os.Unsetenv("GOSH_A")
|
||||
os.Unsetenv("GOSH_L")
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
if funcDepth != 0 || len(localFrames) != 0 || ioOverride != [3]*os.File{} {
|
||||
t.Fatalf("%q: function state not restored", tc.input)
|
||||
}
|
||||
}
|
||||
|
||||
for input, want := range map[string]string{
|
||||
"return": "return: can only `return' from a function or sourced script",
|
||||
"local x": "local: can only be used in a function",
|
||||
"f() { f; }; f": "f: maximum function nesting level exceeded (1000)",
|
||||
"f() echo x": "f: the body of a function must be a compound command like { ...; }",
|
||||
"f() { return x; }; f": "return: x: numeric argument required",
|
||||
} {
|
||||
if err := execInput(input); err == nil || err.Error() != want {
|
||||
t.Errorf("%q: err = %v, want %q", input, err, want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_Case(t *testing.T) {
|
||||
resetShell(t)
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"case abc in a*) echo a > out;; b*) echo b > out;; esac", "a\n"},
|
||||
{"case bcd in a*) echo a > out;; b*) echo b > out;; esac", "b\n"},
|
||||
{"case xyz in a*) echo a > out;; esac", ""},
|
||||
{"case stop in start|run) echo s > out;; stop|halt) echo h > out;; esac", "h\n"},
|
||||
{"case x in (x) echo paren > out;; esac", "paren\n"},
|
||||
{"case x in x)echo tight > out;;esac", "tight\n"},
|
||||
{"case x in x ) echo blank > out ;; esac", "blank\n"},
|
||||
{"case x in\n y) echo y > out ;;\n x)\n echo x1 >> out\n echo x2 >> out\n ;;\nesac", "x1\nx2\n"},
|
||||
// The last clause needs no ;;
|
||||
{"case x in x) echo last > out; esac", "last\n"},
|
||||
{"case x in x) ;; esac; echo empty > out", "empty\n"},
|
||||
{"case x in esac; echo none > out", "none\n"},
|
||||
// Patterns: wildcards, also across /, quoted characters are literal
|
||||
{"case a/b/c in *) echo star > out;; esac", "star\n"},
|
||||
{"case a/b in a?b) echo q > out;; esac", "q\n"},
|
||||
{"case b in [abc]) echo class > out;; esac", "class\n"},
|
||||
{"case d in [!abc]) echo neg > out;; esac", "neg\n"},
|
||||
{`case '*' in "*") echo quoted > out;; *) echo glob > out;; esac`, "quoted\n"},
|
||||
{`case abc in "*") echo quoted > out;; *) echo glob > out;; esac`, "glob\n"},
|
||||
{`case 'a b' in "a b") echo space > out;; esac`, "space\n"},
|
||||
{`case 'x)' in 'x)') echo paren-in-quotes > out;; esac`, "paren-in-quotes\n"},
|
||||
// Variables in the word and in patterns
|
||||
{`set -- --help; case $1 in -h|--help) echo help > out;; esac`, "help\n"},
|
||||
// Values of variables are no patterns (like everywhere in gosh)
|
||||
{`P='b*'; case bar in $P) echo pattern > out;; *) echo literal > out;; esac`, "literal\n"},
|
||||
{`P='b*'; case 'b*' in $P) echo same > out;; esac`, "same\n"},
|
||||
{`case $(echo hi) in hi) echo subst > out;; esac`, "subst\n"},
|
||||
{`case "" in "") echo empty-word > out;; esac`, "empty-word\n"},
|
||||
// Only the first matching clause runs
|
||||
{"case a in a) echo 1 >> out;; *) echo 2 >> out;; esac", "1\n"},
|
||||
// Nested in other structures
|
||||
{"for x in a b; do case $x in a) echo A >> out;; *) echo other >> out;; esac; done", "A\nother\n"},
|
||||
{"f() { case $1 in y) return 0;; *) return 1;; esac; }; f y && echo yes > out", "yes\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
|
||||
for input, status := range map[string]int{
|
||||
"case x in y) false;; esac": 0,
|
||||
"case x in x) false;; esac": 1,
|
||||
"case x in x) true;; esac": 0,
|
||||
"case x in x) echo;": 2,
|
||||
"case x y in x) ;; esac": 2,
|
||||
"echo a;; echo b": 2,
|
||||
} {
|
||||
runIn(t, input)
|
||||
if lastStatus != status {
|
||||
t.Errorf("%q: $? = %d, want %d", input, lastStatus, status)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_Group(t *testing.T) {
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"{ echo a >> out; echo b >> out; }", "a\nb\n"},
|
||||
{"{\n echo multi >> out\n}", "multi\n"},
|
||||
{"false || { echo fallback >> out; }", "fallback\n"},
|
||||
{"echo { } > out", "{ }\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestExec_PositionalBuiltins(t *testing.T) {
|
||||
resetShell(t)
|
||||
tests := []struct {
|
||||
input string
|
||||
want string
|
||||
}{
|
||||
{"set -- a b c; echo $# $1 $3 > out", "3 a c\n"},
|
||||
{"set -- a b c; shift; echo $# $1 > out", "2 b\n"},
|
||||
{"set -- a b c; shift 2; echo $# $1 > out", "1 c\n"},
|
||||
{"set -- a b; shift 3; echo $# $? > out", "2 1\n"},
|
||||
{"set --; echo $# > out", "0\n"},
|
||||
{"set -- a b; for x; do echo $x >> out; done", "a\nb\n"},
|
||||
{"set -- 1 2 3; while [ $# -gt 0 ]; do echo $1 >> out; shift; done", "1\n2\n3\n"},
|
||||
// source with arguments
|
||||
{"echo 'echo $# $1 > out' > lib; set -- x; . ./lib a b", "2 a\n"},
|
||||
{"echo 'echo $1 > out' > lib; set -- x; . ./lib a b; echo $1 >> out", "a\nx\n"},
|
||||
// return ends a sourced file
|
||||
{"printf 'echo one >> out\\nreturn 3\\necho two >> out\\n' > lib; . ./lib; echo $? >> out", "one\n3\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
positional = nil
|
||||
if got := runIn(t, tc.input); got != tc.want {
|
||||
t.Errorf("%q: out = %q, want %q", tc.input, got, tc.want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestRead(t *testing.T) {
|
||||
for _, name := range []string{"GOSH_A", "GOSH_B", "GOSH_C", "REPLY", "IFS"} {
|
||||
os.Unsetenv(name)
|
||||
defer os.Unsetenv(name)
|
||||
}
|
||||
tests := []struct {
|
||||
input string
|
||||
data string
|
||||
want string
|
||||
}{
|
||||
{"read GOSH_A", "hello world\n", "[hello world]"},
|
||||
{"read GOSH_A GOSH_B", " one two three \n", "[one][two three]"},
|
||||
{"read GOSH_A GOSH_B GOSH_C", "one\n", "[one][][]"},
|
||||
{"read GOSH_A", "no newline", "[no newline]"},
|
||||
{"read GOSH_A GOSH_B", `a\ b c` + "\n", "[a b][c]"},
|
||||
{"read -r GOSH_A GOSH_B", `a\ b c` + "\n", `[a\][b c]`},
|
||||
{"read GOSH_A", "con\\\ntinued\n", "[continued]"},
|
||||
{"read", " reply \n", "[ reply ]"},
|
||||
{"IFS=:; read GOSH_A GOSH_B GOSH_C", "a::b:c\n", "[a][][b:c]"},
|
||||
{"IFS=:; read GOSH_A GOSH_B", "a b:c d\n", "[a b][c d]"},
|
||||
{"IFS=; read GOSH_A", " keep \n", "[ keep ]"},
|
||||
{"read GOSH_A; read GOSH_B", "first\nsecond\n", "[first][second]"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
for _, name := range []string{"GOSH_A", "GOSH_B", "GOSH_C", "REPLY", "IFS"} {
|
||||
os.Unsetenv(name)
|
||||
}
|
||||
dir := t.TempDir()
|
||||
in := filepath.Join(dir, "in")
|
||||
os.WriteFile(in, []byte(tc.data), 0644)
|
||||
f, _ := os.Open(in)
|
||||
saved := os.Stdin
|
||||
os.Stdin = f
|
||||
execInput(tc.input)
|
||||
os.Stdin = saved
|
||||
f.Close()
|
||||
|
||||
var got strings.Builder
|
||||
names := []string{"GOSH_A", "GOSH_B", "GOSH_C"}
|
||||
if !strings.Contains(tc.input, "GOSH_") {
|
||||
names = []string{"REPLY"}
|
||||
}
|
||||
for _, name := range names {
|
||||
if v, ok := os.LookupEnv(name); ok {
|
||||
got.WriteString("[" + v + "]")
|
||||
}
|
||||
}
|
||||
if got.String() != tc.want {
|
||||
t.Errorf("%q with %q: got %s, want %s", tc.input, tc.data, got.String(), tc.want)
|
||||
}
|
||||
}
|
||||
|
||||
// Status 1 at the end of the input, also after a last line without newline
|
||||
for data, want := range map[string]int{"line\n": 0, "partial": 1, "": 1} {
|
||||
dir := t.TempDir()
|
||||
os.WriteFile(filepath.Join(dir, "in"), []byte(data), 0644)
|
||||
runIn(t, "read GOSH_A < "+filepath.Join(dir, "in"))
|
||||
if lastStatus != want {
|
||||
t.Errorf("read from %q: $? = %d, want %d", data, lastStatus, want)
|
||||
}
|
||||
}
|
||||
|
||||
if err := execInput("read 1x"); err == nil || err.Error() != "read: `1x': not a valid identifier" {
|
||||
t.Errorf("read 1x: %v", err)
|
||||
}
|
||||
if err := execInput("echo a | read GOSH_A"); err == nil || !strings.Contains(err.Error(), "cannot be used in a pipeline") {
|
||||
t.Errorf("read in a pipeline: %v", err)
|
||||
}
|
||||
}
|
||||
|
||||
// TestShell_Arguments checks $0 and the positional parameters of scripts and
|
||||
// gosh -c, and that a script reads lines from stdin with read.
|
||||
func TestShell_Arguments(t *testing.T) {
|
||||
dir := t.TempDir()
|
||||
script := filepath.Join(dir, "script.gosh")
|
||||
os.WriteFile(script, []byte(`echo "$# [$1] [$2]"
|
||||
usage() {
|
||||
echo "usage: $1" >&2
|
||||
return 2
|
||||
}
|
||||
case ${1:-} in
|
||||
-h) usage x; exit $? ;;
|
||||
esac
|
||||
while read -r line; do
|
||||
echo "line: $line"
|
||||
done
|
||||
`), 0644)
|
||||
|
||||
tests := []struct {
|
||||
args []string
|
||||
stdin string
|
||||
want string
|
||||
}{
|
||||
{[]string{"-c", `echo $0 $# "$@"`}, "", subshellPath + " 0\n"},
|
||||
{[]string{"-c", `echo $0 $# "$@"`, "name", "a", "b c"}, "", "name 2 a b c\n"},
|
||||
{[]string{"-c", `for a; do echo "<$a>"; done`, "n", "x y", "z"}, "", "<x y>\n<z>\n"},
|
||||
{[]string{script, "one", "two words"}, "l1\nl2\n", "2 [one] [two words]\nline: l1\nline: l2\n"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
cmd := exec.Command(subshellPath, tc.args...)
|
||||
cmd.Stdin = strings.NewReader(tc.stdin)
|
||||
out, _ := cmd.Output()
|
||||
if string(out) != tc.want {
|
||||
t.Errorf("gosh %q: got %q, want %q", tc.args, out, tc.want)
|
||||
}
|
||||
}
|
||||
|
||||
cmd := exec.Command(subshellPath, script, "-h")
|
||||
out, err := cmd.CombinedOutput()
|
||||
if exitStatus(err) != 2 || !strings.Contains(string(out), "usage: x") {
|
||||
t.Errorf("script -h: status %d, output %q", exitStatus(err), out)
|
||||
}
|
||||
}
|
||||
+268
@@ -0,0 +1,268 @@
|
||||
package main
|
||||
|
||||
// Here-documents: cmd <<WORD, followed by lines up to a line WORD, is the
|
||||
// same as a here-string cmd <<<"lines" (without the last newline, which the
|
||||
// here-string adds). extractHeredocs rewrites the source that way before it
|
||||
// is parsed, so that the rest of gosh (and subshells, which get the source
|
||||
// text) only has to know here-strings.
|
||||
|
||||
import (
|
||||
"strings"
|
||||
)
|
||||
|
||||
// hereDoc is a here-document whose body has not been read yet.
|
||||
type hereDoc struct {
|
||||
seg int // the index of its placeholder in the output segments
|
||||
delim string
|
||||
quoted bool // the delimiter was quoted: the body is not expanded
|
||||
stripTabs bool // <<-: leading tabs are removed from the lines
|
||||
}
|
||||
|
||||
// extractHeredocs replaces every here-document operator in src by a
|
||||
// here-string with its body and removes the body and delimiter lines. The
|
||||
// body starts after the end of the line with the operator. If the input
|
||||
// ends before the delimiter line, it returns errIncomplete (an interactive
|
||||
// shell then reads more lines).
|
||||
//
|
||||
// The body is expanded like "..." if the delimiter is unquoted ($VAR, $(...),
|
||||
// \ before $ ` \ and newline), and taken literally if any part of the
|
||||
// delimiter is quoted ('EOF', "EOF", \EOF).
|
||||
func extractHeredocs(src string) (string, error) {
|
||||
if !strings.Contains(src, "<<") {
|
||||
return src, nil
|
||||
}
|
||||
var (
|
||||
segs []string
|
||||
cur strings.Builder
|
||||
pending []hereDoc
|
||||
wordStart = true
|
||||
)
|
||||
copyTo := func(i, end int) int {
|
||||
if end < 0 || end > len(src) {
|
||||
end = len(src)
|
||||
}
|
||||
cur.WriteString(src[i:end])
|
||||
return end
|
||||
}
|
||||
|
||||
for i := 0; i < len(src); {
|
||||
ch := src[i]
|
||||
switch {
|
||||
case ch == '\\':
|
||||
i = copyTo(i, i+2)
|
||||
wordStart = false
|
||||
case ch == '\'':
|
||||
end := strings.IndexByte(src[i+1:], '\'')
|
||||
if end >= 0 {
|
||||
end += i + 2
|
||||
}
|
||||
i = copyTo(i, end)
|
||||
wordStart = false
|
||||
case ch == '"':
|
||||
end := dquoteEnd(src, i)
|
||||
if end >= 0 {
|
||||
end++
|
||||
}
|
||||
i = copyTo(i, end)
|
||||
wordStart = false
|
||||
case isSubstStart(src, i):
|
||||
end := substEnd(src, i)
|
||||
if end >= 0 {
|
||||
end++
|
||||
}
|
||||
i = copyTo(i, end)
|
||||
wordStart = false
|
||||
case ch == '#' && wordStart:
|
||||
// A comment, until the end of the line
|
||||
end := strings.IndexByte(src[i:], '\n')
|
||||
if end >= 0 {
|
||||
end += i
|
||||
}
|
||||
i = copyTo(i, end)
|
||||
case strings.HasPrefix(src[i:], "<<<"):
|
||||
i = copyTo(i, i+3)
|
||||
wordStart = false
|
||||
case strings.HasPrefix(src[i:], "<<"):
|
||||
h, n, err := parseHereOp(src[i:])
|
||||
if err != nil {
|
||||
return "", err
|
||||
}
|
||||
segs = append(segs, cur.String())
|
||||
cur.Reset()
|
||||
h.seg = len(segs)
|
||||
segs = append(segs, "") // filled in when the body has been read
|
||||
pending = append(pending, h)
|
||||
i += n
|
||||
wordStart = false
|
||||
case ch == '\n':
|
||||
cur.WriteByte(ch)
|
||||
i++
|
||||
wordStart = true
|
||||
// The bodies of the here-documents of this line follow
|
||||
for _, h := range pending {
|
||||
body, n, ok := readHereBody(src[i:], h)
|
||||
if !ok {
|
||||
return "", errIncomplete
|
||||
}
|
||||
segs[h.seg] = hereString(body, h.quoted)
|
||||
i += n
|
||||
}
|
||||
pending = nil
|
||||
default:
|
||||
cur.WriteByte(ch)
|
||||
i++
|
||||
wordStart = strings.IndexByte(" \t;&|()<>", ch) >= 0
|
||||
}
|
||||
}
|
||||
if len(pending) > 0 {
|
||||
return "", errIncomplete
|
||||
}
|
||||
segs = append(segs, cur.String())
|
||||
return strings.Join(segs, ""), nil
|
||||
}
|
||||
|
||||
// dquoteEnd returns the index of the " that ends the double-quoted string
|
||||
// starting at s[i], or -1.
|
||||
func dquoteEnd(s string, i int) int {
|
||||
for j := i + 1; j < len(s); j++ {
|
||||
switch {
|
||||
case s[j] == '\\':
|
||||
j++
|
||||
case isSubstStart(s, j):
|
||||
end := substEnd(s, j)
|
||||
if end < 0 {
|
||||
return -1
|
||||
}
|
||||
j = end
|
||||
case s[j] == '"':
|
||||
return j
|
||||
}
|
||||
}
|
||||
return -1
|
||||
}
|
||||
|
||||
// parseHereOp parses a here-document operator <<WORD or <<-WORD at the
|
||||
// start of s and returns it and its length.
|
||||
func parseHereOp(s string) (hereDoc, int, error) {
|
||||
h := hereDoc{}
|
||||
i := 2
|
||||
if i < len(s) && s[i] == '-' {
|
||||
h.stripTabs = true
|
||||
i++
|
||||
}
|
||||
for i < len(s) && (s[i] == ' ' || s[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
var delim strings.Builder
|
||||
start := i
|
||||
for i < len(s) && strings.IndexByte(" \t\n;&|()<>", s[i]) < 0 {
|
||||
switch c := s[i]; c {
|
||||
case '\'', '"':
|
||||
end := strings.IndexByte(s[i+1:], c)
|
||||
if end < 0 {
|
||||
return h, 0, errIncomplete
|
||||
}
|
||||
delim.WriteString(s[i+1 : i+1+end])
|
||||
i += end + 2
|
||||
h.quoted = true
|
||||
case '\\':
|
||||
if i+1 < len(s) {
|
||||
delim.WriteByte(s[i+1])
|
||||
}
|
||||
i += 2
|
||||
h.quoted = true
|
||||
default:
|
||||
delim.WriteByte(c)
|
||||
i++
|
||||
}
|
||||
}
|
||||
if i == start {
|
||||
if i == len(s) || s[i] == '\n' {
|
||||
return h, 0, syntaxError("newline")
|
||||
}
|
||||
return h, 0, syntaxError(s[i : i+1])
|
||||
}
|
||||
h.delim = delim.String()
|
||||
return h, min(i, len(s)), nil
|
||||
}
|
||||
|
||||
// readHereBody reads the lines of a here-document from s up to the
|
||||
// delimiter line. It returns the body (each line with its newline) and the
|
||||
// number of bytes consumed, or ok == false if there is no delimiter line yet.
|
||||
func readHereBody(s string, h hereDoc) (body string, n int, ok bool) {
|
||||
var b strings.Builder
|
||||
for pos := 0; ; {
|
||||
end := strings.IndexByte(s[pos:], '\n')
|
||||
last := end < 0
|
||||
if last {
|
||||
end = len(s) - pos
|
||||
}
|
||||
line := s[pos : pos+end]
|
||||
if h.stripTabs {
|
||||
line = strings.TrimLeft(line, "\t")
|
||||
}
|
||||
next := min(pos+end+1, len(s))
|
||||
if line == h.delim {
|
||||
return b.String(), next, true
|
||||
}
|
||||
if last {
|
||||
return "", 0, false
|
||||
}
|
||||
b.WriteString(line)
|
||||
b.WriteByte('\n')
|
||||
pos = next
|
||||
}
|
||||
}
|
||||
|
||||
// hereString returns the here-string (or redirection) that has the effect of
|
||||
// a here-document with the given body.
|
||||
func hereString(body string, quoted bool) string {
|
||||
if body == "" {
|
||||
return "</dev/null"
|
||||
}
|
||||
body = strings.TrimSuffix(body, "\n")
|
||||
if quoted {
|
||||
return "<<<'" + strings.ReplaceAll(body, "'", `'\''`) + "'"
|
||||
}
|
||||
return `<<<"` + escapeHereBody(body) + `"`
|
||||
}
|
||||
|
||||
// escapeHereBody quotes the body of an unquoted here-document for "...":
|
||||
// " becomes \", a backslash that only escapes $ ` \ and newline in a
|
||||
// here-document stays one, others become \\. $(...) and ${...} are kept as
|
||||
// they are, "$@" becomes "$*" (one word, as in a here-document).
|
||||
func escapeHereBody(body string) string {
|
||||
var b strings.Builder
|
||||
for i := 0; i < len(body); i++ {
|
||||
c := body[i]
|
||||
switch {
|
||||
case isSubstStart(body, i):
|
||||
end := substEnd(body, i)
|
||||
if end < 0 {
|
||||
end = len(body) - 1
|
||||
}
|
||||
b.WriteString(body[i : end+1])
|
||||
i = end
|
||||
case strings.HasPrefix(body[i:], "$@"):
|
||||
b.WriteString("$*")
|
||||
i++
|
||||
case strings.HasPrefix(body[i:], "${"):
|
||||
end := strings.IndexByte(body[i:], '}')
|
||||
if end < 0 {
|
||||
end = len(body) - i - 1
|
||||
}
|
||||
b.WriteString(strings.Replace(body[i:i+end+1], "${@", "${*", 1))
|
||||
i += end
|
||||
case c == '\\' && i+1 < len(body) && strings.IndexByte("$`\\\n", body[i+1]) >= 0:
|
||||
b.WriteString(body[i : i+2])
|
||||
i++
|
||||
case c == '\\':
|
||||
b.WriteString(`\\`)
|
||||
case c == '"':
|
||||
b.WriteString(`\"`)
|
||||
default:
|
||||
b.WriteByte(c)
|
||||
}
|
||||
}
|
||||
return b.String()
|
||||
}
|
||||
@@ -12,6 +12,7 @@ import (
|
||||
"os/user"
|
||||
"path/filepath"
|
||||
"runtime/debug"
|
||||
"slices"
|
||||
"sort"
|
||||
"strconv"
|
||||
"strings"
|
||||
@@ -121,6 +122,7 @@ type token struct {
|
||||
word string // the word, if op == ""
|
||||
pattern string // the word as glob pattern (quoted characters escaped)
|
||||
glob bool // the word contains unquoted * ? or [ and is expanded
|
||||
assign bool // the word is an assignment name=value (unquoted name and =)
|
||||
fd int // the redirected file descriptor (for redirections)
|
||||
dup int // the target file descriptor of >& and <&
|
||||
}
|
||||
@@ -136,7 +138,8 @@ type token struct {
|
||||
// - $VAR, ${VAR} and ${VAR:-default} are expanded outside single quotes;
|
||||
// an unset variable is an error, so that e.g. "rm -rf $DIR/x" never runs
|
||||
// with an empty $DIR
|
||||
// - ~ and ~/... are expanded at the start of an unquoted word
|
||||
// - ~ and ~/... are expanded at the start of an unquoted word, and after
|
||||
// the = and : of an assignment (PATH=~/bin:~/go/bin)
|
||||
// - unquoted |, <, >, >>, N<, N>, N>>, N>&M, N<&M, &> and &>> are operators
|
||||
//
|
||||
// Expanded values are never split into several words.
|
||||
@@ -147,23 +150,29 @@ func tokenize(input string) ([]token, error) {
|
||||
pat strings.Builder // the word as glob pattern, quoted parts escaped
|
||||
glob bool // the word contains unquoted * ? or [
|
||||
inWord bool // a word has been started (even if it is still empty)
|
||||
plain = true // the word so far has no quotes, escapes or expansions
|
||||
assign bool // the word is an assignment name=value
|
||||
tildeOK bool // ~ may be expanded here (after = or : of an assignment)
|
||||
noParams bool // the word contains "$@" without positional parameters
|
||||
quote byte
|
||||
escaped bool
|
||||
rawStart = -1 // start of the current word in input
|
||||
)
|
||||
|
||||
endWord := func() {
|
||||
if inWord {
|
||||
tokens = append(tokens, token{word: b.String(), pattern: pat.String(), glob: glob})
|
||||
// "$@" without parameters is no word at all, unlike ""
|
||||
if inWord && !(noParams && b.Len() == 0) {
|
||||
tokens = append(tokens, token{word: b.String(), pattern: pat.String(), glob: glob, assign: assign})
|
||||
}
|
||||
b.Reset()
|
||||
pat.Reset()
|
||||
glob = false
|
||||
glob, assign, plain, noParams = false, false, true, false
|
||||
inWord = false
|
||||
rawStart = -1
|
||||
}
|
||||
// literal adds quoted, escaped or expanded text: it is never a pattern
|
||||
literal := func(s string) {
|
||||
plain = false
|
||||
b.WriteString(s)
|
||||
pat.WriteString(escapeGlob(s))
|
||||
}
|
||||
@@ -175,19 +184,21 @@ func tokenize(input string) ([]token, error) {
|
||||
|
||||
for i := 0; i < len(input); i++ {
|
||||
ch := input[i]
|
||||
afterAssignSep := tildeOK
|
||||
tildeOK = false
|
||||
switch {
|
||||
case escaped:
|
||||
if quote == '"' && !strings.ContainsRune("$\"\\`", rune(ch)) {
|
||||
literal("\\")
|
||||
}
|
||||
literal(string(ch))
|
||||
literal(input[i : i+1])
|
||||
inWord = true
|
||||
escaped = false
|
||||
case quote == '\'':
|
||||
if ch == '\'' {
|
||||
quote = 0
|
||||
} else {
|
||||
literal(string(ch))
|
||||
literal(input[i : i+1])
|
||||
}
|
||||
case ch == '\\':
|
||||
startRaw(i)
|
||||
@@ -202,7 +213,8 @@ func tokenize(input string) ([]token, error) {
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if quote == '"' {
|
||||
if quote == '"' || assign {
|
||||
// Quoted or in an assignment, the output is one word
|
||||
literal(out)
|
||||
inWord = true
|
||||
} else {
|
||||
@@ -218,6 +230,20 @@ func tokenize(input string) ([]token, error) {
|
||||
}
|
||||
}
|
||||
i = end
|
||||
case ch == '$' && !assign && positionalWords(input[i:], quote == '"') > 0:
|
||||
// $@ and "$@": one word per positional parameter
|
||||
startRaw(i)
|
||||
if len(positional) == 0 && quote == '"' {
|
||||
noParams = true
|
||||
}
|
||||
for k, param := range positional {
|
||||
if k > 0 {
|
||||
endWord()
|
||||
}
|
||||
literal(param)
|
||||
inWord = true
|
||||
}
|
||||
i += positionalWords(input[i:], quote == '"') - 1
|
||||
case ch == '$':
|
||||
startRaw(i)
|
||||
value, n, err := expandVar(input[i:])
|
||||
@@ -237,10 +263,11 @@ func tokenize(input string) ([]token, error) {
|
||||
if ch == '"' {
|
||||
quote = 0
|
||||
} else {
|
||||
literal(string(ch))
|
||||
literal(input[i : i+1])
|
||||
}
|
||||
case ch == '"' || ch == '\'':
|
||||
startRaw(i)
|
||||
plain = false
|
||||
quote = ch
|
||||
inWord = true
|
||||
case ch == ' ' || ch == '\t' || ch == '\n':
|
||||
@@ -279,6 +306,10 @@ func tokenize(input string) ([]token, error) {
|
||||
}
|
||||
t := token{op: string(ch), fd: fd}
|
||||
switch {
|
||||
case strings.HasPrefix(input[i:], "<<<"):
|
||||
// <<<word: the word (and a newline) is the input
|
||||
t.op = "<<<"
|
||||
i += 2
|
||||
case ch == '>' && i+1 < len(input) && input[i+1] == '>':
|
||||
t.op = ">>"
|
||||
i++
|
||||
@@ -296,8 +327,8 @@ func tokenize(input string) ([]token, error) {
|
||||
i = j - 1
|
||||
}
|
||||
tokens = append(tokens, t)
|
||||
case ch == '~' && !inWord && b.Len() == 0 &&
|
||||
(i+1 == len(input) || strings.IndexByte("/ \t\n|<>", input[i+1]) >= 0):
|
||||
case ch == '~' && (!inWord && b.Len() == 0 || afterAssignSep) &&
|
||||
(i+1 == len(input) || strings.IndexByte("/ \t\n|<>:", input[i+1]) >= 0):
|
||||
startRaw(i)
|
||||
home := getHomeDir()
|
||||
if home == "" {
|
||||
@@ -307,6 +338,14 @@ func tokenize(input string) ([]token, error) {
|
||||
inWord = true
|
||||
default:
|
||||
startRaw(i)
|
||||
switch {
|
||||
case ch == '=' && plain && !assign && isVarName(b.String()):
|
||||
// name=value; ~ may follow
|
||||
assign, tildeOK = true, true
|
||||
case ch == ':' && assign:
|
||||
// PATH=~/bin:~/go/bin
|
||||
tildeOK = true
|
||||
}
|
||||
b.WriteByte(ch)
|
||||
switch {
|
||||
case ch == '*' || ch == '?' || ch == '[':
|
||||
@@ -488,13 +527,10 @@ func expandVar(s string) (string, int, error) {
|
||||
return "", 0, errors.New("missing } in variable reference")
|
||||
}
|
||||
name, def, hasDef := strings.Cut(s[2:end], ":-")
|
||||
if name == "?" {
|
||||
return strconv.Itoa(lastStatus), end + 1, nil
|
||||
}
|
||||
if !isVarName(name) {
|
||||
if !isVarName(name) && !isDigits(name) && !isSpecialParam(name) {
|
||||
return "", 0, fmt.Errorf("bad substitution: %s", s[:end+1])
|
||||
}
|
||||
value, ok := os.LookupEnv(name)
|
||||
value, ok := lookupParam(name)
|
||||
if hasDef && value == "" {
|
||||
return def, end + 1, nil
|
||||
}
|
||||
@@ -504,8 +540,13 @@ func expandVar(s string) (string, int, error) {
|
||||
return value, end + 1, nil
|
||||
}
|
||||
|
||||
if len(s) > 1 && s[1] == '?' {
|
||||
return strconv.Itoa(lastStatus), 2, nil
|
||||
// $?, $#, $$, $@, $*, $0 and $1 to $9 ($10 is $1 followed by 0)
|
||||
if len(s) > 1 && (isSpecialParam(s[1:2]) || isDigits(s[1:2])) {
|
||||
value, ok := lookupParam(s[1:2])
|
||||
if !ok {
|
||||
return "", 0, fmt.Errorf("%s: unbound variable", s[1:2])
|
||||
}
|
||||
return value, 2, nil
|
||||
}
|
||||
|
||||
n := 1
|
||||
@@ -522,6 +563,25 @@ func expandVar(s string) (string, int, error) {
|
||||
return value, n, nil
|
||||
}
|
||||
|
||||
// isSpecialParam reports whether name is one of the special parameters ?,
|
||||
// #, $, @ and *.
|
||||
func isSpecialParam(name string) bool {
|
||||
return len(name) == 1 && strings.Contains("?#$@*", name)
|
||||
}
|
||||
|
||||
// positionalWords returns the number of bytes of $@ or ${@} at the start of
|
||||
// s, which expands to one word per positional parameter (also in double
|
||||
// quotes). Unquoted, $* and ${*} do the same (gosh never splits values).
|
||||
// It returns 0 for anything else.
|
||||
func positionalWords(s string, quoted bool) int {
|
||||
for _, p := range []string{"$@", "${@}", "$*", "${*}"} {
|
||||
if strings.HasPrefix(s, p) && (strings.Contains(p, "@") || !quoted) {
|
||||
return len(p)
|
||||
}
|
||||
}
|
||||
return 0
|
||||
}
|
||||
|
||||
func isVarName(name string) bool {
|
||||
if name == "" {
|
||||
return false
|
||||
@@ -742,7 +802,7 @@ type shellCompleter struct {
|
||||
|
||||
func newShellCompleter() *shellCompleter {
|
||||
return &shellCompleter{
|
||||
commands: []string{"cd", "pwd", "echo", "exit", "quit", "set", "export", "source", "jobs", "fg", "bg", "wait", "alias", "unalias", "break", "continue", "help"},
|
||||
commands: []string{"cd", "pwd", "echo", "exit", "quit", "set", "export", "source", "jobs", "fg", "bg", "wait", "alias", "unalias", "break", "continue", "unset", "help", "return", "local", "shift", "read"},
|
||||
}
|
||||
}
|
||||
|
||||
@@ -759,7 +819,7 @@ func (c *shellCompleter) Do(line []rune, pos int) ([][]rune, int) {
|
||||
// ... and after if, then, do etc.
|
||||
if fields := strings.Fields(before); len(fields) > 0 {
|
||||
switch fields[len(fields)-1] {
|
||||
case "if", "then", "elif", "else", "do", "while", "until", "!":
|
||||
case "if", "then", "elif", "else", "do", "while", "until", "!", "{", ";;":
|
||||
isFirstWord = true
|
||||
}
|
||||
}
|
||||
@@ -773,7 +833,7 @@ func (c *shellCompleter) Do(line []rune, pos int) ([][]rune, int) {
|
||||
// Complete commands
|
||||
var candidates [][]rune
|
||||
seen := make(map[string]bool)
|
||||
names := append(append(append([]string(nil), c.commands...), aliasNames()...), pathExecutables(word)...)
|
||||
names := append(append(append(append([]string(nil), c.commands...), aliasNames()...), functionNames()...), pathExecutables(word)...)
|
||||
for _, cmd := range names {
|
||||
if strings.HasPrefix(cmd, word) && !seen[cmd] {
|
||||
seen[cmd] = true
|
||||
@@ -917,8 +977,8 @@ func completeFilePath(line, prefix string) []string {
|
||||
return matches
|
||||
}
|
||||
|
||||
const usage = `usage: gosh [-l] [-i] [--norc] [--noprofile] [script]
|
||||
gosh [-l] [--noprofile] -c command
|
||||
const usage = `usage: gosh [-l] [-i] [--norc] [--noprofile] [script [args ...]]
|
||||
gosh [-l] [--noprofile] -c command [name [args ...]]
|
||||
gosh -version`
|
||||
|
||||
// sysConfDir holds the system-wide startup files.
|
||||
@@ -931,6 +991,7 @@ func main() {
|
||||
if strings.HasPrefix(os.Args[0], "-") {
|
||||
args = append([]string{"-l"}, args...)
|
||||
}
|
||||
scriptName = os.Args[0]
|
||||
os.Exit(run(args))
|
||||
}
|
||||
|
||||
@@ -968,21 +1029,26 @@ flags:
|
||||
fmt.Println(usage)
|
||||
return 0
|
||||
case arg == "-c":
|
||||
// Like sh, further arguments are allowed (they would become $0,
|
||||
// $1, ...), but gosh has no positional parameters yet.
|
||||
// gosh -c command [name [args ...]]: name is $0, args are $1, ...
|
||||
if len(args) < 2 {
|
||||
fmt.Fprintln(os.Stderr, "gosh: -c: option requires an argument")
|
||||
fmt.Fprintln(os.Stderr, usage)
|
||||
return 2
|
||||
}
|
||||
if len(args) > 2 {
|
||||
scriptName, positional = args[2], args[3:]
|
||||
}
|
||||
script = func() int { return runScript(strings.NewReader(args[1]), "") }
|
||||
case strings.HasPrefix(arg, "-") && arg != "-":
|
||||
fmt.Fprintf(os.Stderr, "gosh: %s: invalid option\n", arg)
|
||||
fmt.Fprintln(os.Stderr, usage)
|
||||
return 2
|
||||
case arg == "-":
|
||||
positional = args[1:]
|
||||
script = func() int { return runScript(os.Stdin, "") }
|
||||
default:
|
||||
// gosh script [args ...]
|
||||
scriptName, positional = arg, args[1:]
|
||||
f, err := os.Open(arg)
|
||||
if err != nil {
|
||||
fmt.Fprintln(os.Stderr, "gosh:", err)
|
||||
@@ -1046,6 +1112,8 @@ func sourceStartupFile(path string) {
|
||||
return
|
||||
}
|
||||
defer f.Close()
|
||||
sourceDepth++
|
||||
defer func() { sourceDepth-- }()
|
||||
runScript(bufio.NewReader(f), path)
|
||||
}
|
||||
|
||||
@@ -1109,12 +1177,18 @@ func runScript(r io.Reader, name string) int {
|
||||
goto next // read the rest of the command
|
||||
}
|
||||
buf.Reset()
|
||||
if err != nil {
|
||||
lastStatus = exitStatus(err)
|
||||
report(err, startLine)
|
||||
} else {
|
||||
report(tree.exec(), startLine)
|
||||
if err == nil {
|
||||
err = tree.exec()
|
||||
var ret returnSignal
|
||||
if errors.As(err, &ret) {
|
||||
// return in a sourced file
|
||||
lastStatus = ret.status
|
||||
return lastStatus
|
||||
}
|
||||
} else {
|
||||
lastStatus = exitStatus(err)
|
||||
}
|
||||
report(err, startLine)
|
||||
}
|
||||
next:
|
||||
if readErr != nil {
|
||||
@@ -1174,6 +1248,10 @@ func exitStatus(err error) int {
|
||||
if errors.As(err, &lc) {
|
||||
return 0
|
||||
}
|
||||
var ret returnSignal
|
||||
if errors.As(err, &ret) {
|
||||
return ret.status
|
||||
}
|
||||
var exitErr *exec.ExitError
|
||||
if errors.As(err, &exitErr) {
|
||||
if ws, ok := exitErr.Sys().(syscall.WaitStatus); ok && ws.Signaled() {
|
||||
@@ -1321,11 +1399,12 @@ func printError(err error) {
|
||||
exitErr *exec.ExitError
|
||||
statusErr statusError
|
||||
lc loopControl
|
||||
ret returnSignal
|
||||
)
|
||||
if err == nil || errors.As(err, &exitErr) || errors.As(err, &statusErr) || errors.As(err, &lc) {
|
||||
if err == nil || errors.As(err, &exitErr) || errors.As(err, &statusErr) || errors.As(err, &lc) || errors.As(err, &ret) {
|
||||
return
|
||||
}
|
||||
fmt.Fprintln(os.Stderr, "gosh:", err)
|
||||
fmt.Fprintln(stdio(2), "gosh:", err)
|
||||
}
|
||||
|
||||
// execInput parses and executes input: a command line or a whole script.
|
||||
@@ -1343,27 +1422,8 @@ func execInput(input string) error {
|
||||
// execCommand executes a pipeline of simple commands with redirections, in
|
||||
// the background if background is set.
|
||||
func execCommand(input string, background bool) error {
|
||||
// Brace expansion comes first, so that its results are expanded further
|
||||
substStatus = 0
|
||||
input, err := expandBraceWords(input)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Split the input into words and operators, expanding variables and ~ on
|
||||
// the way.
|
||||
tokens, err := tokenize(input)
|
||||
var (
|
||||
synErr syntaxError
|
||||
statusErr statusError
|
||||
)
|
||||
if errors.As(err, &synErr) || errors.As(err, &statusErr) {
|
||||
return err
|
||||
}
|
||||
if err != nil {
|
||||
return fmt.Errorf("invalid input: %w", err)
|
||||
}
|
||||
stages, err := parsePipeline(tokens)
|
||||
stages, err := expandStages(input)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
@@ -1381,18 +1441,62 @@ func execCommand(input string, background bool) error {
|
||||
return runPipeline(stages, strings.TrimSpace(input), background)
|
||||
}
|
||||
|
||||
// redirect is a redirection of a simple command, e.g. 2>>file or 2>&1.
|
||||
type redirect struct {
|
||||
op string // <, >, >>, &>, &>>, >& or <&
|
||||
fd int // the redirected file descriptor
|
||||
dup int // the target file descriptor of >& and <&
|
||||
file string // the file name for all other operators
|
||||
// expandStages expands the text of a pipeline of simple commands and splits
|
||||
// it into its stages.
|
||||
func expandStages(input string) ([]stage, error) {
|
||||
// Brace expansion comes first, so that its results are expanded further
|
||||
input, err := expandBraceWords(input)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// Split the input into words and operators, expanding variables and ~ on
|
||||
// the way.
|
||||
tokens, err := tokenize(input)
|
||||
var (
|
||||
synErr syntaxError
|
||||
statusErr statusError
|
||||
)
|
||||
if errors.As(err, &synErr) || errors.As(err, &statusErr) {
|
||||
return nil, err
|
||||
}
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("invalid input: %w", err)
|
||||
}
|
||||
return parsePipeline(tokens)
|
||||
}
|
||||
|
||||
// stage is a simple command of a pipeline.
|
||||
// openRedirections expands and opens the redirections of a compound command
|
||||
// and returns the resulting stdin, stdout and stderr, and the files to close
|
||||
// afterwards.
|
||||
func openRedirections(text string) ([3]*os.File, []*os.File, error) {
|
||||
fds := [3]*os.File{stdio(0), stdio(1), stdio(2)}
|
||||
stages, err := expandStages(text)
|
||||
if err != nil {
|
||||
return fds, nil, err
|
||||
}
|
||||
if len(stages) != 1 || len(stages[0].args) > 0 || len(stages[0].assigns) > 0 {
|
||||
return fds, nil, syntaxError(text)
|
||||
}
|
||||
opened, err := applyRedirects(&fds, stages[0].redirects)
|
||||
return fds, opened, err
|
||||
}
|
||||
|
||||
// redirect is a redirection of a simple command, e.g. 2>>file or 2>&1.
|
||||
type redirect struct {
|
||||
op string // <, >, >>, &>, &>>, >&, <& or <<<
|
||||
fd int // the redirected file descriptor
|
||||
dup int // the target file descriptor of >& and <&
|
||||
file string // the file name for all other operators (the text for <<<)
|
||||
}
|
||||
|
||||
// stage is a simple command of a pipeline, or a script that runs in a
|
||||
// subshell (a compound command in a pipeline or in the background).
|
||||
type stage struct {
|
||||
assigns []string // name=value before the command name
|
||||
args []string
|
||||
redirects []redirect
|
||||
script string
|
||||
}
|
||||
|
||||
// parsePipeline groups tokens into the stages of a pipeline.
|
||||
@@ -1401,13 +1505,18 @@ func parsePipeline(tokens []token) ([]stage, error) {
|
||||
stages []stage
|
||||
cur stage
|
||||
)
|
||||
isEmpty := func(s stage) bool { return len(s.args) == 0 && len(s.redirects) == 0 }
|
||||
isEmpty := func(s stage) bool { return len(s.assigns) == 0 && len(s.args) == 0 && len(s.redirects) == 0 }
|
||||
|
||||
for i := 0; i < len(tokens); i++ {
|
||||
t := tokens[i]
|
||||
switch t.op {
|
||||
case "":
|
||||
if t.assign && len(cur.args) == 0 {
|
||||
// The value is not split and not expanded as a pattern
|
||||
cur.assigns = append(cur.assigns, t.word)
|
||||
} else {
|
||||
cur.args = append(cur.args, expandWord(t)...)
|
||||
}
|
||||
case "|":
|
||||
if isEmpty(cur) {
|
||||
return nil, syntaxError("|")
|
||||
@@ -1424,6 +1533,11 @@ func parsePipeline(tokens []token) ([]stage, error) {
|
||||
return nil, syntaxError(next.op)
|
||||
}
|
||||
i++
|
||||
if t.op == "<<<" {
|
||||
// A here-string is not expanded as a pattern
|
||||
cur.redirects = append(cur.redirects, redirect{op: t.op, fd: t.fd, file: tokens[i].word})
|
||||
continue
|
||||
}
|
||||
files := expandWord(tokens[i])
|
||||
if len(files) > 1 {
|
||||
return nil, fmt.Errorf("%s: ambiguous redirect", sanitize(tokens[i].word))
|
||||
@@ -1452,7 +1566,7 @@ func runPipeline(stages []stage, text string, background bool) error {
|
||||
shellTTY, _ = readline.GetState(ttyFd)
|
||||
}
|
||||
|
||||
stdin := os.Stdin
|
||||
stdin := stdio(0)
|
||||
if background && !jobControl {
|
||||
// Without job control background jobs must not read from the
|
||||
// terminal, like in sh
|
||||
@@ -1462,12 +1576,12 @@ func runPipeline(stages []stage, text string, background bool) error {
|
||||
}
|
||||
var startErr error
|
||||
for i, st := range stages {
|
||||
stdout := os.Stdout
|
||||
stdout := stdio(1)
|
||||
var next *os.File
|
||||
if i < len(stages)-1 {
|
||||
r, w, err := os.Pipe()
|
||||
if err != nil {
|
||||
if stdin != os.Stdin {
|
||||
if stdin != stdio(0) {
|
||||
stdin.Close()
|
||||
}
|
||||
startErr = err
|
||||
@@ -1507,10 +1621,10 @@ func runPipeline(stages []stage, text string, background bool) error {
|
||||
// longer needs them, so that the neighbors see EOF or get SIGPIPE.
|
||||
func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background bool) *proc {
|
||||
var owned []*os.File
|
||||
if stdin != os.Stdin {
|
||||
if stdin != stdio(0) {
|
||||
owned = append(owned, stdin)
|
||||
}
|
||||
if stdout != os.Stdout {
|
||||
if stdout != stdio(1) {
|
||||
owned = append(owned, stdout)
|
||||
}
|
||||
closeOwned := func() {
|
||||
@@ -1523,16 +1637,39 @@ func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background
|
||||
// the command would read from /dev/null, so interactive programs (su,
|
||||
// vim, ssh, ...) would get EOF right away. readline only reads from stdin
|
||||
// while a line is being edited, so it does not steal input.
|
||||
fds := [3]*os.File{stdin, stdout, os.Stderr}
|
||||
fds := [3]*os.File{stdin, stdout, stdio(2)}
|
||||
opened, err := applyRedirects(&fds, st.redirects)
|
||||
owned = append(owned, opened...)
|
||||
if err != nil || len(st.args) == 0 {
|
||||
if err == nil && len(st.args) == 0 && len(st.assigns) > 0 {
|
||||
// Assignments without a command set variables of the shell (not in
|
||||
// a pipeline or in the background, where sh runs them in a
|
||||
// subshell). The status is the one of the last $(...) in them.
|
||||
if !inPipeline && !background {
|
||||
for _, a := range st.assigns {
|
||||
name, value, _ := strings.Cut(a, "=")
|
||||
os.Setenv(name, value)
|
||||
}
|
||||
}
|
||||
if substStatus != 0 {
|
||||
err = statusError(substStatus)
|
||||
}
|
||||
}
|
||||
if err != nil || len(st.args) == 0 && st.script == "" {
|
||||
// A command without arguments only creates or truncates the files
|
||||
closeOwned()
|
||||
return finishedProc(err)
|
||||
}
|
||||
|
||||
if builtin, ok := builtins[st.args[0]]; ok {
|
||||
var fn *funcDef
|
||||
isFunc := false
|
||||
if st.script == "" {
|
||||
fn, isFunc = functions[st.args[0]]
|
||||
}
|
||||
if isFunc && !inPipeline && !background {
|
||||
defer closeOwned()
|
||||
return finishedProc(callFunction(fn, st.args, fds, st.assigns))
|
||||
}
|
||||
if builtin, ok := builtins[firstArg(st.args)]; !isFunc && st.script == "" && ok {
|
||||
switch {
|
||||
case inPipeline && builtin.changesState:
|
||||
closeOwned()
|
||||
@@ -1541,10 +1678,11 @@ func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background
|
||||
closeOwned()
|
||||
return finishedProc(fmt.Errorf("%s: cannot be run in the background", st.args[0]))
|
||||
}
|
||||
shellStderr := stdio(2)
|
||||
run := func() error {
|
||||
defer closeOwned()
|
||||
err := runBuiltin(st.args, fds[1])
|
||||
if err != nil && fds[2] != os.Stderr {
|
||||
err := runBuiltin(st.args, fds[0], fds[1])
|
||||
if err != nil && fds[2] != shellStderr {
|
||||
// Report the error where stderr is redirected to
|
||||
fmt.Fprintln(fds[2], "gosh:", err)
|
||||
return statusError(1)
|
||||
@@ -1552,6 +1690,12 @@ func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background
|
||||
return err
|
||||
}
|
||||
if !inPipeline && !background {
|
||||
// name=value before a builtin applies only while it runs, its
|
||||
// redirections also to the commands it runs (source file > out)
|
||||
defer setTemporarily(st.assigns)()
|
||||
saved := ioOverride
|
||||
ioOverride = fds
|
||||
defer func() { ioOverride = saved }()
|
||||
return finishedProc(run())
|
||||
}
|
||||
p := &proc{done: make(chan error, 1)}
|
||||
@@ -1559,8 +1703,29 @@ func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background
|
||||
return p
|
||||
}
|
||||
|
||||
cmd := exec.Command(st.args[0], st.args[1:]...)
|
||||
var cmd *exec.Cmd
|
||||
if st.script != "" {
|
||||
cmd, err = subshellCommand(st.script, positional)
|
||||
if err != nil {
|
||||
closeOwned()
|
||||
return finishedProc(err)
|
||||
}
|
||||
} else if isFunc {
|
||||
// A function in a pipeline or in the background runs in a subshell
|
||||
cmd, err = subshellCommand(`"$@"`, st.args)
|
||||
if err != nil {
|
||||
closeOwned()
|
||||
return finishedProc(err)
|
||||
}
|
||||
} else {
|
||||
cmd = exec.Command(st.args[0], st.args[1:]...)
|
||||
}
|
||||
cmd.Stdin, cmd.Stdout, cmd.Stderr = fds[0], fds[1], fds[2]
|
||||
if len(st.assigns) > 0 {
|
||||
// name=value before a command is only in its environment (the
|
||||
// last value of a name wins)
|
||||
cmd.Env = append(os.Environ(), st.assigns...)
|
||||
}
|
||||
if jobControl {
|
||||
// All processes of the job share a process group: the one of the
|
||||
// first process. In the foreground, the first process makes its
|
||||
@@ -1578,7 +1743,7 @@ func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background
|
||||
// The child has its own copies of the files now
|
||||
closeOwned()
|
||||
if errors.Is(err, exec.ErrNotFound) {
|
||||
err = fmt.Errorf("%s: %w", sanitize(st.args[0]), errCommandNotFound)
|
||||
err = fmt.Errorf("%s: %w", sanitize(firstArg(st.args)), errCommandNotFound)
|
||||
}
|
||||
if err != nil {
|
||||
return finishedProc(err)
|
||||
@@ -1593,6 +1758,38 @@ func startStage(st stage, stdin, stdout *os.File, j *job, inPipeline, background
|
||||
return &proc{cmd: cmd}
|
||||
}
|
||||
|
||||
func firstArg(args []string) string {
|
||||
if len(args) == 0 {
|
||||
return ""
|
||||
}
|
||||
return args[0]
|
||||
}
|
||||
|
||||
// setTemporarily sets the variables of the assignments and returns a
|
||||
// function that restores the previous values.
|
||||
func setTemporarily(assigns []string) func() {
|
||||
type saved struct {
|
||||
name, value string
|
||||
ok bool
|
||||
}
|
||||
var restore []saved
|
||||
for _, a := range assigns {
|
||||
name, value, _ := strings.Cut(a, "=")
|
||||
old, ok := os.LookupEnv(name)
|
||||
restore = append(restore, saved{name, old, ok})
|
||||
os.Setenv(name, value)
|
||||
}
|
||||
return func() {
|
||||
for i := len(restore) - 1; i >= 0; i-- {
|
||||
if r := restore[i]; r.ok {
|
||||
os.Setenv(r.name, r.value)
|
||||
} else {
|
||||
os.Unsetenv(r.name)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// applyRedirects applies the redirections in order to fds (stdin, stdout,
|
||||
// stderr) and returns the files it opened.
|
||||
func applyRedirects(fds *[3]*os.File, redirects []redirect) ([]*os.File, error) {
|
||||
@@ -1616,6 +1813,16 @@ func applyRedirects(fds *[3]*os.File, redirects []redirect) ([]*os.File, error)
|
||||
continue
|
||||
}
|
||||
|
||||
if r.op == "<<<" {
|
||||
f, err := hereFile(r.file + "\n")
|
||||
if err != nil {
|
||||
return fail(err)
|
||||
}
|
||||
opened = append(opened, f)
|
||||
fds[r.fd] = f
|
||||
continue
|
||||
}
|
||||
|
||||
flags := os.O_WRONLY | os.O_CREATE | os.O_TRUNC
|
||||
switch r.op {
|
||||
case "<":
|
||||
@@ -1641,6 +1848,26 @@ func applyRedirects(fds *[3]*os.File, redirects []redirect) ([]*os.File, error)
|
||||
return opened, nil
|
||||
}
|
||||
|
||||
// hereFile returns a file to read content from: a temporary file that is
|
||||
// already removed (like bash does for here-documents), so that large inputs
|
||||
// work and nothing is left behind.
|
||||
func hereFile(content string) (*os.File, error) {
|
||||
f, err := os.CreateTemp("", "gosh-here-*")
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
os.Remove(f.Name())
|
||||
if _, err := f.WriteString(content); err != nil {
|
||||
f.Close()
|
||||
return nil, err
|
||||
}
|
||||
if _, err := f.Seek(0, io.SeekStart); err != nil {
|
||||
f.Close()
|
||||
return nil, err
|
||||
}
|
||||
return f, nil
|
||||
}
|
||||
|
||||
// builtins lists the built-in commands. Commands that change the state of
|
||||
// the shell cannot be used in a pipeline, since there they would run
|
||||
// concurrently (sh runs them in a subshell where they have no effect).
|
||||
@@ -1661,12 +1888,18 @@ var builtins = map[string]struct{ changesState bool }{
|
||||
"alias": {},
|
||||
"unalias": {changesState: true},
|
||||
":": {},
|
||||
"unset": {changesState: true},
|
||||
"break": {changesState: true},
|
||||
"continue": {changesState: true},
|
||||
"return": {changesState: true},
|
||||
"local": {changesState: true},
|
||||
"shift": {changesState: true},
|
||||
"read": {changesState: true},
|
||||
}
|
||||
|
||||
// runBuiltin executes a built-in command, writing its output to stdout.
|
||||
func runBuiltin(args []string, stdout io.Writer) error {
|
||||
// runBuiltin executes a built-in command, reading from stdin and writing its
|
||||
// output to stdout.
|
||||
func runBuiltin(args []string, stdin *os.File, stdout io.Writer) error {
|
||||
switch args[0] {
|
||||
case "cd":
|
||||
// Save current directory before changing (for 'cd -')
|
||||
@@ -1719,6 +1952,11 @@ func runBuiltin(args []string, stdout io.Writer) error {
|
||||
}
|
||||
return exitShell(lastStatus)
|
||||
case "set":
|
||||
// set -- args: set the positional parameters
|
||||
if len(args) > 1 && args[1] == "--" {
|
||||
positional = slices.Clone(args[2:])
|
||||
return nil
|
||||
}
|
||||
// set VAR=value - set environment variable
|
||||
if len(args) < 2 {
|
||||
return fmt.Errorf("usage: set VAR=value")
|
||||
@@ -1745,8 +1983,39 @@ func runBuiltin(args []string, stdout io.Writer) error {
|
||||
case ":":
|
||||
// Does nothing, successfully (e.g. while :; do ...)
|
||||
return nil
|
||||
case "unset":
|
||||
// unset [-v] NAME ... - remove variables, unset -f NAME ... - functions
|
||||
names := args[1:]
|
||||
funcs := len(names) > 0 && names[0] == "-f"
|
||||
if len(names) > 0 && (names[0] == "-f" || names[0] == "-v") {
|
||||
names = names[1:]
|
||||
}
|
||||
if len(names) == 0 {
|
||||
return fmt.Errorf("usage: unset [-f|-v] NAME ...")
|
||||
}
|
||||
var err error
|
||||
for _, name := range names {
|
||||
if funcs {
|
||||
delete(functions, name)
|
||||
continue
|
||||
}
|
||||
if !isVarName(name) {
|
||||
err = fmt.Errorf("unset: `%s': not a valid identifier", sanitize(name))
|
||||
continue
|
||||
}
|
||||
os.Unsetenv(name)
|
||||
}
|
||||
return err
|
||||
case "break", "continue":
|
||||
return builtinLoopControl(args)
|
||||
case "return":
|
||||
return builtinReturn(args)
|
||||
case "local":
|
||||
return builtinLocal(args)
|
||||
case "shift":
|
||||
return builtinShift(args)
|
||||
case "read":
|
||||
return builtinRead(args, stdin)
|
||||
case "alias":
|
||||
return builtinAlias(args, stdout)
|
||||
case "unalias":
|
||||
@@ -1760,9 +2029,15 @@ func runBuiltin(args []string, stdout io.Writer) error {
|
||||
case "wait":
|
||||
return builtinWait(args)
|
||||
case "source", ".":
|
||||
// source file - run the commands of file in the current shell
|
||||
// source file [args] - run the commands of file in the current shell
|
||||
if len(args) < 2 {
|
||||
return fmt.Errorf("usage: %s file", args[0])
|
||||
return fmt.Errorf("usage: %s file [args ...]", args[0])
|
||||
}
|
||||
if len(args) > 2 {
|
||||
// The arguments are the positional parameters while it runs
|
||||
saved := positional
|
||||
positional = slices.Clone(args[2:])
|
||||
defer func() { positional = saved }()
|
||||
}
|
||||
return sourceFile(args[0], args[1])
|
||||
case "help":
|
||||
@@ -1775,8 +2050,10 @@ Built-in commands:
|
||||
exit [code] - Exit shell with status code (default: $?)
|
||||
quit [code] - Quit shell with status code (default: $?)
|
||||
set VAR=val - Set environment variable
|
||||
set -- args - Set the positional parameters $1, $2, ...
|
||||
export VAR=val - Export environment variable
|
||||
source file - Run the commands of file in this shell (also: . file)
|
||||
unset VAR - Remove a variable (unset -f name: a function)
|
||||
source file [args] - Run the commands of file in this shell (also: . file)
|
||||
jobs - List background and stopped jobs
|
||||
fg [%n] - Continue job n (default: current job) in the foreground
|
||||
bg [%n] - Continue stopped job n in the background
|
||||
@@ -1786,6 +2063,12 @@ Built-in commands:
|
||||
: - Do nothing (exit status 0)
|
||||
break [n] - Leave the innermost (or n-th) for/while/until loop
|
||||
continue [n] - Continue with the next iteration of a loop
|
||||
return [n] - Leave a function or sourced file with status n
|
||||
local VAR[=val] - Variable that gets its old value back when the
|
||||
function returns
|
||||
shift [n] - Remove the first n positional parameters (default 1)
|
||||
read [-r] [-p prompt] [VAR ...] - Read a line into variables (split
|
||||
at $IFS; the last one gets the rest; default $REPLY)
|
||||
help - Show this help
|
||||
|
||||
Features:
|
||||
@@ -1808,8 +2091,14 @@ Features:
|
||||
GOSH_COLORS='user=1;33:path=36' (keys user, root, path, error; values
|
||||
are ANSI SGR codes, empty = no color); disabled with $NO_COLOR,
|
||||
TERM=dumb or when output is not a terminal
|
||||
- Variables: name=value sets a variable (like set), name=value command
|
||||
sets it only for that command; the value is not split or expanded as
|
||||
a pattern
|
||||
- Environment variable expansion ($VAR, ${VAR}, ${VAR:-default});
|
||||
using an unset variable is an error, use ${VAR:-} for an empty default
|
||||
- Positional parameters: $0, $1 ... $9, ${10}, $# (count), "$@" (one
|
||||
word each), "$*" (one word), $$ (process ID); set by gosh script
|
||||
args, gosh -c command name args, functions, set -- and source
|
||||
- Command substitution: $(command) is replaced by the output of command
|
||||
(run in a subshell); unquoted it is split into words, "$(command)"
|
||||
stays one word
|
||||
@@ -1817,9 +2106,16 @@ Features:
|
||||
a || b (b only if a failed); $? is the exit status of the last command
|
||||
- Control structures: if cmd; then ...; elif cmd; then ...; else ...; fi,
|
||||
for x in words; do ...; done, while cmd; do ...; done, until ...,
|
||||
! cmd negates the status; they can span several lines (prompt "> ")
|
||||
case word in pattern|pattern) ...;; esac, { cmd; cmd; } groups,
|
||||
( cmd; cmd ) subshells; ! cmd negates the status; they can span
|
||||
several lines (prompt "> "), have redirections (done < file) and can
|
||||
be used in pipes (| while read l; do ...; done) and with &
|
||||
- Functions: name() { ...; } (or function name { ...; }); the arguments
|
||||
are $1, $2, ...; in pipes, & and $(...) they run in a subshell
|
||||
- Pipes (a | b) and redirections: < file, > file, >> file, 2> file,
|
||||
2>> file, 2>&1, >&2, &> file (stdout and stderr), &>> file
|
||||
2>> file, 2>&1, >&2, &> file (stdout and stderr), &>> file,
|
||||
<<EOF here-documents (<<-EOF strips tabs, <<'EOF' expands nothing),
|
||||
<<<word here-strings
|
||||
- Job control: command & runs in the background, Ctrl+Z stops the
|
||||
foreground job; jobs, fg, bg and wait manage the jobs
|
||||
- Aliases replace the first word of a command in interactive shells
|
||||
|
||||
+51
-7
@@ -941,7 +941,7 @@ func TestSplitWords(t *testing.T) {
|
||||
{`echo x${GOSH_A}y`, []string{"echo", "xa by"}},
|
||||
// Escaped and lone dollar signs stay literal
|
||||
{`echo \$GOSH_A "\$GOSH_A"`, []string{"echo", "$GOSH_A", "$GOSH_A"}},
|
||||
{`echo $ 5$ $1`, []string{"echo", "$", "5$", "$1"}},
|
||||
{`echo $ 5$ $%`, []string{"echo", "$", "5$", "$%"}},
|
||||
// Backslash in double quotes only escapes $ " \ and `
|
||||
{`echo "a\nb\\c"`, []string{"echo", `a\nb\c`}},
|
||||
// Defaults
|
||||
@@ -1437,6 +1437,26 @@ func pipelineString(pl *pipelineNode) string {
|
||||
s += "while "
|
||||
}
|
||||
s += treeString(n.cond) + " do " + treeString(n.body) + " done"
|
||||
case *caseNode:
|
||||
s += "case " + n.word + " in"
|
||||
for _, c := range n.clauses {
|
||||
s += " (" + strings.Join(c.patterns, "|") + ") " + treeString(c.body) + " ;;"
|
||||
}
|
||||
s += " esac"
|
||||
case *groupNode:
|
||||
s += "{ " + treeString(n.body) + " }"
|
||||
case *subshellNode:
|
||||
s += "(" + n.text + ")"
|
||||
case *redirNode:
|
||||
s += pipelineString(&pipelineNode{cmd: n.cmd}) + " <" + n.redirs + ">"
|
||||
case *pipeNode:
|
||||
var elems []string
|
||||
for _, e := range n.elems {
|
||||
elems = append(elems, "<"+e.text+">")
|
||||
}
|
||||
s += strings.Join(elems, " | ")
|
||||
case *funcDefNode:
|
||||
s += n.def.name + "() " + pipelineString(&pipelineNode{cmd: n.def.body})
|
||||
}
|
||||
return s
|
||||
}
|
||||
@@ -1504,6 +1524,27 @@ func TestParse_ControlStructures(t *testing.T) {
|
||||
{"while a; do if b; then break; fi; done", "while [a] do if [b] then [break] fi done"},
|
||||
{"for i in 1 2; do for j in 3 4; do echo $i$j; done; done", "for i in (1 2) do for j in (3 4) do [echo $i$j] done done"},
|
||||
{"if a; then if b; then c; fi fi", "if [a] then if [b] then [c] fi fi"},
|
||||
// Compound commands in pipelines, with redirections, in the background
|
||||
{"for x in a; do b; done | cat", "<for x in a; do b; done> | <cat>"},
|
||||
{"a | while b; do c; done | d", "<a> | <while b; do c; done> | <d>"},
|
||||
{"if a; then b; fi > out 2>&1", "if [a] then [b] fi <> out 2>&1>"},
|
||||
{"while read l; do b; done < in", "while [read l] do [b] done << in>"},
|
||||
{"{ a; b; } 2> err", "{ [a]; [b] } <2> err>"},
|
||||
{"for x in a; do b; done &", "for x in (a) do [b] done &"},
|
||||
{"a && b &", "[a] && [b] &"},
|
||||
// Subshells
|
||||
{"(a; b)", "(a; b)"},
|
||||
{"( a ) | b", "<( a )> | <b>"},
|
||||
{"(a) > f", "(a) <> f>"},
|
||||
{"(a; (b)) && c", "(a; (b)) && [c]"},
|
||||
// case, groups and functions
|
||||
{"case $x in a|b) c;; (d) e; f;; esac", "case $x in (a|b) [c] ;; (d) [e]; [f] ;; esac"},
|
||||
{"case x in\n a)\n b\n ;;\nesac", "case x in (a) [b] ;; esac"},
|
||||
{"{ a; }", "{ [a] }"},
|
||||
{"f() { a; }", "f() { [a] }"},
|
||||
{"f ( ) { a; }", "f() { [a] }"},
|
||||
{"function f { a; }", "f() { [a] }"},
|
||||
{"f() (a)", "f() (a)"},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
tree, err := parse(tc.input)
|
||||
@@ -1522,6 +1563,8 @@ func TestParse_Incomplete(t *testing.T) {
|
||||
"if a", "if a; then", "if a; then b", "if a; then b; else", "if a; then b; elif c",
|
||||
"for x", "for x in a b", "for x in a; do", "for x in a; do b",
|
||||
"while a", "while a; do b", "until a; do",
|
||||
"(a", "(a; b", "{ a;", "case x in", "case x in a) b;;", "f() {", "f()",
|
||||
"cat <<EOF", "cat <<EOF\nbody", "cat <<'EOF'\nbody\nEO",
|
||||
"a &&", "a ||", "a |", "echo 'open", `echo "open`, "echo $(a", "echo a \\",
|
||||
} {
|
||||
if _, err := parse(input); !errors.Is(err, errIncomplete) {
|
||||
@@ -1536,6 +1579,9 @@ func TestParse_SyntaxErrors(t *testing.T) {
|
||||
"fi", "then", "done", "if a; then fi", "if ; then a; fi", "while a; do done",
|
||||
"if a; then b; done", "for 1x in a; do b; done", "for x in a do b; done; x",
|
||||
"a | | b", "| a",
|
||||
"()", "a (", "a )", "echo (a)", ")", "(a) b", "if a; then b; fi c", "{ a; } b",
|
||||
"case x in a b) c;; esac", "case x in ) a;; esac", "cat <<", "cat << ;",
|
||||
"f() { a; } | b",
|
||||
} {
|
||||
_, err := parse(input)
|
||||
if err == nil || errors.Is(err, errIncomplete) {
|
||||
@@ -1543,11 +1589,9 @@ func TestParse_SyntaxErrors(t *testing.T) {
|
||||
}
|
||||
}
|
||||
for input, want := range map[string]string{
|
||||
"for x in a; do b; done | cat": "control structures in pipelines are not supported",
|
||||
"echo | while a; do b; done": "control structures in pipelines are not supported",
|
||||
"if a; then b; fi > out": "redirections of control structures are not supported (near `>')",
|
||||
"for x in a; do b; done &": "only simple commands and pipelines can run in the background",
|
||||
"a && b &": "only simple commands and pipelines can run in the background",
|
||||
"f() { a; } | b": "function definitions in pipelines are not supported",
|
||||
"f() { a; } > out": "redirections of function definitions are not supported",
|
||||
"if a; then b; fi c": "syntax error near unexpected token `c'",
|
||||
} {
|
||||
if _, err := parse(input); err == nil || err.Error() != want {
|
||||
t.Errorf("parse(%q) = %v, want %q", input, err, want)
|
||||
@@ -1674,7 +1718,7 @@ func TestTokenize_Operators(t *testing.T) {
|
||||
}
|
||||
// Patterns are tested in TestTokenize_Patterns
|
||||
for i := range got {
|
||||
got[i].pattern, got[i].glob = "", false
|
||||
got[i].pattern, got[i].glob, got[i].assign = "", false, false
|
||||
}
|
||||
if !reflect.DeepEqual(got, tc.want) {
|
||||
t.Errorf("tokenize(%q) = %+v, want %+v", tc.input, got, tc.want)
|
||||
|
||||
@@ -0,0 +1,678 @@
|
||||
.\" Man page for gosh. View with: man ./packaging/man/gosh.1
|
||||
.\" @VERSION@ is replaced by the release version when building packages.
|
||||
.TH GOSH 1 "October 2026" "gosh @VERSION@" "User Commands"
|
||||
.SH NAME
|
||||
gosh \- a simple shell written in Go
|
||||
.SH SYNOPSIS
|
||||
.B gosh
|
||||
.RB [ \-l ]
|
||||
.RB [ \-i ]
|
||||
.RB [ \-\-norc ]
|
||||
.RB [ \-\-noprofile ]
|
||||
.RI [ script
|
||||
.RI [ args " ...]]"
|
||||
.br
|
||||
.B gosh
|
||||
.RB [ \-l ]
|
||||
.RB [ \-\-noprofile ]
|
||||
.B \-c
|
||||
.I command
|
||||
.RI [ name
|
||||
.RI [ args " ...]]"
|
||||
.br
|
||||
.B gosh
|
||||
.B \-version
|
||||
.SH DESCRIPTION
|
||||
.B gosh
|
||||
is a small command interpreter with a syntax close to
|
||||
.BR sh (1).
|
||||
It supports command history, tab completion, variables, positional
|
||||
parameters, command substitution, command lists, control structures,
|
||||
functions, pipes, redirections, wildcards, brace expansion, aliases and job
|
||||
control.
|
||||
.PP
|
||||
Without arguments and with a terminal on standard input,
|
||||
.B gosh
|
||||
starts an interactive shell. With a
|
||||
.I script
|
||||
argument it runs the commands of that file, with
|
||||
.B \-c
|
||||
the given command string, and otherwise it reads commands from standard
|
||||
input. The
|
||||
.I args
|
||||
after the script, or after the
|
||||
.I name
|
||||
of
|
||||
.BR \-c ,
|
||||
become the positional parameters
|
||||
.BR $1 ,
|
||||
.BR $2 ", ..."
|
||||
.PP
|
||||
.B gosh
|
||||
is a proof of concept and not meant for production use.
|
||||
.SH OPTIONS
|
||||
.TP
|
||||
.B \-c \fIcommand\fP [\fIname\fP [\fIargs\fP ...]]
|
||||
Run
|
||||
.I command
|
||||
and exit.
|
||||
.I name
|
||||
becomes
|
||||
.BR $0 ,
|
||||
the
|
||||
.I args
|
||||
become
|
||||
.BR $1 ,
|
||||
.BR $2 ", ..."
|
||||
.TP
|
||||
.B \-i
|
||||
Force interactive mode, even if standard input is not a terminal.
|
||||
.TP
|
||||
.BR \-l ", " \-\-login
|
||||
Act as a login shell and read the profile files (see
|
||||
.BR "STARTUP FILES" ).
|
||||
A shell whose
|
||||
.I argv[0]
|
||||
starts with
|
||||
.B \-
|
||||
(as started by
|
||||
.BR login (1),
|
||||
.BR sshd (8)
|
||||
or
|
||||
.BR "su \-" )
|
||||
is a login shell as well.
|
||||
.TP
|
||||
.B \-\-norc
|
||||
Do not read the goshrc files.
|
||||
.TP
|
||||
.B \-\-noprofile
|
||||
Do not read the profile files.
|
||||
.TP
|
||||
.BR \-version ", " \-\-version ", " \-V
|
||||
Print the version, branch and commit and exit.
|
||||
.TP
|
||||
.BR \-h ", " \-\-help
|
||||
Print a usage summary and exit.
|
||||
.TP
|
||||
.B \-
|
||||
Read commands from standard input.
|
||||
.SH NON-INTERACTIVE USE
|
||||
Scripts, command strings and commands read from a pipe are executed line
|
||||
by line. Empty lines and lines starting with
|
||||
.B #
|
||||
are skipped, so a script may start with
|
||||
.BR "#!/usr/bin/gosh" .
|
||||
A failing command does not abort the script; the exit status of
|
||||
.B gosh
|
||||
is the one of the last command.
|
||||
.PP
|
||||
Because
|
||||
.B gosh
|
||||
supports
|
||||
.BR \-c ,
|
||||
.BR ssh (1),
|
||||
.BR scp (1)
|
||||
and
|
||||
.BR rsync (1)
|
||||
work when it is used as login shell.
|
||||
.SH STARTUP FILES
|
||||
Startup files are executed in the running shell, so variables and
|
||||
aliases defined there stay in effect.
|
||||
.TP
|
||||
Login shells
|
||||
read
|
||||
.I /etc/gosh/profile
|
||||
and
|
||||
.IR ~/.gosh_profile .
|
||||
.TP
|
||||
Interactive shells
|
||||
read
|
||||
.I /etc/gosh/goshrc
|
||||
and
|
||||
.IR ~/.goshrc .
|
||||
.PP
|
||||
An interactive login shell reads the profile files first, then the goshrc
|
||||
files. Scripts and
|
||||
.B \-c
|
||||
read no startup files unless
|
||||
.B gosh
|
||||
is a login shell. Missing files are skipped; errors are reported with file
|
||||
name and line number and the remaining lines still run. Files of other
|
||||
shells such as
|
||||
.I /etc/profile
|
||||
or
|
||||
.I ~/.bashrc
|
||||
are not read.
|
||||
.SH SYNTAX
|
||||
.SS Quoting
|
||||
.TP
|
||||
.B \(aq...\(aq
|
||||
Everything is literal.
|
||||
.TP
|
||||
.B \(dq...\(dq
|
||||
Variables and command substitutions are expanded, the result stays one
|
||||
word.
|
||||
.TP
|
||||
.B \e
|
||||
Escapes the next character.
|
||||
.SS Variables
|
||||
.TP
|
||||
.I name\fB=\fPvalue
|
||||
Set a variable. All variables are exported to the environment of started
|
||||
programs. The value is not split into words and not expanded as a pattern;
|
||||
variables, command substitutions and
|
||||
.B ~
|
||||
(at the start, after
|
||||
.B =
|
||||
and after
|
||||
.BR : )
|
||||
are expanded.
|
||||
.TP
|
||||
.I name\fB=\fPvalue command
|
||||
Set the variable only for
|
||||
.IR command .
|
||||
.TP
|
||||
.BR $VAR ", " ${VAR}
|
||||
The value of
|
||||
.BR VAR .
|
||||
Using an unset variable is an error and aborts the command.
|
||||
.TP
|
||||
.B ${VAR:\-default}
|
||||
The value of
|
||||
.BR VAR ,
|
||||
or
|
||||
.I default
|
||||
if it is unset or empty. Use
|
||||
.B ${VAR:\-}
|
||||
for an empty default.
|
||||
.TP
|
||||
.B $?
|
||||
The exit status of the last command.
|
||||
.SS Positional parameters
|
||||
.TP
|
||||
.B $0
|
||||
The name of the script, or the
|
||||
.I name
|
||||
given after
|
||||
.BR "gosh \-c" .
|
||||
.TP
|
||||
.BR $1 " ... " $9 ", " ${10}
|
||||
The arguments of the script, of
|
||||
.BR "gosh \-c" ,
|
||||
of a function call or of
|
||||
.BR source ,
|
||||
or the words set with
|
||||
.BR "set \-\-" .
|
||||
An unset parameter is an error like an unset variable; use
|
||||
.B ${1:\-}
|
||||
for an optional argument.
|
||||
.TP
|
||||
.B $#
|
||||
The number of positional parameters.
|
||||
.TP
|
||||
.B \(dq$@\(dq
|
||||
All positional parameters, each as a separate word. Without parameters it
|
||||
expands to no word at all.
|
||||
.TP
|
||||
.B \(dq$*\(dq
|
||||
All positional parameters as one word, separated by blanks.
|
||||
.TP
|
||||
.B $$
|
||||
The process ID of the shell.
|
||||
.SS Command substitution
|
||||
.B $(\fIcommand\fP)
|
||||
is replaced by the output of
|
||||
.IR command ,
|
||||
which runs in a subshell. Trailing newlines are removed. Unquoted, the
|
||||
output is split into words at blanks and newlines; inside double quotes it
|
||||
stays one word. Wildcards and operators in the output are not interpreted.
|
||||
Backticks and arithmetic expansion are not supported.
|
||||
.SS Tilde and brace expansion
|
||||
.B ~
|
||||
and
|
||||
.B ~/path
|
||||
at the start of an unquoted word are replaced by the home directory.
|
||||
.PP
|
||||
Brace expansion generates several words from one:
|
||||
.B a{b,c}d
|
||||
becomes
|
||||
.BR "abd acd" ,
|
||||
.B {1..5}
|
||||
becomes
|
||||
.BR "1 2 3 4 5" ,
|
||||
.B {01..10..4}
|
||||
becomes
|
||||
.B 01 05 09
|
||||
and
|
||||
.B {a..e}
|
||||
becomes
|
||||
.BR "a b c d e" .
|
||||
Brace expansion happens before all other expansions.
|
||||
.SS Wildcards
|
||||
.B *
|
||||
matches any string,
|
||||
.B ?
|
||||
any single character,
|
||||
.B [abc]
|
||||
and
|
||||
.B [a\-z]
|
||||
one of the given characters and
|
||||
.B [!abc]
|
||||
(or
|
||||
.BR [^abc] )
|
||||
any character except those. Matches are sorted. Hidden files are only
|
||||
matched if the pattern starts with a dot. A pattern without match is kept
|
||||
unchanged. Quoted wildcards and values of variables are never expanded.
|
||||
.SS Command lists
|
||||
.TP
|
||||
.IB a " ; " b
|
||||
Run
|
||||
.IR a ,
|
||||
then
|
||||
.IR b .
|
||||
.TP
|
||||
.IB a " && " b
|
||||
Run
|
||||
.I b
|
||||
only if
|
||||
.I a
|
||||
succeeded.
|
||||
.TP
|
||||
.IB a " || " b
|
||||
Run
|
||||
.I b
|
||||
only if
|
||||
.I a
|
||||
failed.
|
||||
.TP
|
||||
.IB command " &"
|
||||
Run
|
||||
.I command
|
||||
in the background.
|
||||
.SS Pipes and redirections
|
||||
.TP
|
||||
.IB a " | " b
|
||||
Connect standard output of
|
||||
.I a
|
||||
to standard input of
|
||||
.IR b .
|
||||
The exit status is the one of
|
||||
.IR b .
|
||||
.TP
|
||||
.BI < " file"
|
||||
Read standard input from
|
||||
.IR file .
|
||||
.TP
|
||||
.BR > " \fIfile\fP, " >> " \fIfile\fP"
|
||||
Write (or append) standard output to
|
||||
.IR file .
|
||||
.TP
|
||||
.BR 2> " \fIfile\fP, " 2>> " \fIfile\fP"
|
||||
Write (or append) standard error to
|
||||
.IR file .
|
||||
.TP
|
||||
.B 2>&1
|
||||
Redirect standard error to where standard output goes.
|
||||
.TP
|
||||
.B >&2
|
||||
Redirect standard output to where standard error goes.
|
||||
.TP
|
||||
.BR &> " \fIfile\fP, " &>> " \fIfile\fP"
|
||||
Write (or append) standard output and standard error to
|
||||
.IR file .
|
||||
.TP
|
||||
.BI << word
|
||||
Here-document: the lines after the command, up to a line that is exactly
|
||||
.IR word ,
|
||||
are standard input. If no part of
|
||||
.I word
|
||||
is quoted, variables, command substitutions and backslashes before
|
||||
.BR $ ,
|
||||
.BR \(ga ,
|
||||
.B \e
|
||||
and newline are expanded in the lines.
|
||||
.BI <<\- word
|
||||
also removes leading tabs from the lines and the delimiter line.
|
||||
.TP
|
||||
.BI <<< " word"
|
||||
Here-string:
|
||||
.I word
|
||||
and a newline are standard input.
|
||||
.PP
|
||||
Redirections are evaluated from left to right. Only file descriptors 0, 1
|
||||
and 2 are supported.
|
||||
.SS Control structures
|
||||
.nf
|
||||
\fBif\fP \fIlist\fP; \fBthen\fP \fIlist\fP; [\fBelif\fP \fIlist\fP; \fBthen\fP \fIlist\fP;] [\fBelse\fP \fIlist\fP;] \fBfi\fP
|
||||
\fBfor\fP \fIname\fP \fBin\fP \fIwords\fP; \fBdo\fP \fIlist\fP; \fBdone\fP
|
||||
\fBwhile\fP \fIlist\fP; \fBdo\fP \fIlist\fP; \fBdone\fP
|
||||
\fBuntil\fP \fIlist\fP; \fBdo\fP \fIlist\fP; \fBdone\fP
|
||||
\fBcase\fP \fIword\fP \fBin\fP [\fB(\fP]\fIpattern\fP[\fB|\fP\fIpattern\fP]...\fB)\fP \fIlist\fP \fB;;\fP ... \fBesac\fP
|
||||
\fB{\fP \fIlist\fP; \fB}\fP
|
||||
\fB(\fP \fIlist\fP \fB)\fP
|
||||
\fB!\fP \fIcommand\fP
|
||||
.fi
|
||||
.PP
|
||||
Control structures may span several lines; an incomplete command shows
|
||||
the continuation prompt
|
||||
.BR "> " .
|
||||
.B !
|
||||
negates the exit status of a command.
|
||||
.B for
|
||||
without
|
||||
.B in
|
||||
loops over the positional parameters.
|
||||
.PP
|
||||
.B case
|
||||
runs the list of the first clause with a pattern that matches
|
||||
.IR word .
|
||||
Patterns are wildcards as for file names, but
|
||||
.B *
|
||||
and
|
||||
.B ?
|
||||
also match a
|
||||
.BR / ;
|
||||
quoted characters match literally, and values of variables are not
|
||||
patterns. The
|
||||
.B ;;
|
||||
of the last clause may be omitted.
|
||||
.PP
|
||||
.B {
|
||||
.IR list ;
|
||||
.B }
|
||||
groups commands; they run in the current shell.
|
||||
.B (
|
||||
.I list
|
||||
.B )
|
||||
runs the commands in a subshell, a new
|
||||
.B gosh
|
||||
process, so that changes of the directory, variables and functions only
|
||||
apply there.
|
||||
.PP
|
||||
Redirections after a control structure
|
||||
.RB ( "done < file" ,
|
||||
.BR "fi > log 2>&1" )
|
||||
apply to all commands in it, which still run in the current shell. In a
|
||||
pipe and in the background
|
||||
.RB ( & ),
|
||||
a control structure runs in a subshell, like in
|
||||
.BR sh (1).
|
||||
The subshell knows the functions and positional parameters of the shell.
|
||||
.SS Functions
|
||||
.nf
|
||||
\fIname\fP\fB() {\fP \fIlist\fP; \fB}\fP
|
||||
\fBfunction\fP \fIname\fP \fB{\fP \fIlist\fP; \fB}\fP
|
||||
.fi
|
||||
.PP
|
||||
defines a function; the body can be any compound command. When the
|
||||
function is called, its arguments are the positional parameters, which get
|
||||
their old values back afterwards. Functions run in the current shell, so
|
||||
variables they set stay set; use
|
||||
.B local
|
||||
for variables that belong to the function. Redirections of a call apply to
|
||||
all commands of the function. In pipes, in the background and in
|
||||
.B $(...)
|
||||
a function runs in a subshell that knows all functions. Functions take
|
||||
precedence over builtins and programs of the same name. Calls can be nested
|
||||
up to a depth of 1000.
|
||||
.SS Aliases
|
||||
In interactive shells, the first word of a command is replaced by its
|
||||
alias. If the alias value ends with a blank, the next word is checked for
|
||||
an alias as well.
|
||||
.B \e\fIname\fP
|
||||
or
|
||||
.B \(aq\fIname\fP\(aq
|
||||
skips the alias. Aliases are not used in scripts and with
|
||||
.BR \-c .
|
||||
.SH BUILTIN COMMANDS
|
||||
.TP
|
||||
.BR cd " [\fIdir\fP]"
|
||||
Change the directory; without argument to the home directory.
|
||||
.TP
|
||||
.B pwd
|
||||
Print the working directory.
|
||||
.TP
|
||||
.BR echo " [\fIargs\fP]"
|
||||
Print the arguments.
|
||||
.TP
|
||||
.BR exit " [\fIcode\fP], " quit " [\fIcode\fP]"
|
||||
Exit the shell with status
|
||||
.I code
|
||||
(default:
|
||||
.BR $? ).
|
||||
.TP
|
||||
.BI set " VAR" = value
|
||||
Set a variable.
|
||||
.TP
|
||||
.BR "set \-\-" " [\fIargs\fP ...]"
|
||||
Set the positional parameters.
|
||||
.TP
|
||||
.BI export " VAR" = value
|
||||
Export a variable.
|
||||
.TP
|
||||
.BR unset " [\fB\-v\fP] \fIVAR\fP ..., " "unset \-f" " \fIname\fP ..."
|
||||
Remove variables, or functions.
|
||||
.TP
|
||||
.BR source " \fIfile\fP [\fIargs\fP ...], " . " \fIfile\fP [\fIargs\fP ...]"
|
||||
Run the commands of
|
||||
.I file
|
||||
in the current shell, with
|
||||
.I args
|
||||
as positional parameters if given.
|
||||
.TP
|
||||
.B jobs
|
||||
List background and stopped jobs.
|
||||
.TP
|
||||
.BR fg " [\fB%\fP\fIn\fP]"
|
||||
Continue job
|
||||
.I n
|
||||
(default: the current job) in the foreground.
|
||||
.TP
|
||||
.BR bg " [\fB%\fP\fIn\fP]"
|
||||
Continue stopped job
|
||||
.I n
|
||||
in the background.
|
||||
.TP
|
||||
.BR wait " [\fB%\fP\fIn\fP]"
|
||||
Wait for job
|
||||
.I n
|
||||
or for all background jobs.
|
||||
.TP
|
||||
.BR alias " [\fIname\fP[\fB=\fP\fIvalue\fP] ...]"
|
||||
Define or show aliases.
|
||||
.TP
|
||||
.BR unalias " \fIname\fP, " "unalias \-a"
|
||||
Remove an alias, or all aliases.
|
||||
.TP
|
||||
.B :
|
||||
Do nothing, exit status 0.
|
||||
.TP
|
||||
.BR break " [\fIn\fP], " continue " [\fIn\fP]"
|
||||
Leave the innermost (or
|
||||
.IR n -th)
|
||||
loop, or continue with its next iteration.
|
||||
.TP
|
||||
.BR return " [\fIn\fP]"
|
||||
Leave a function or sourced file with status
|
||||
.I n
|
||||
(default:
|
||||
.BR $? ).
|
||||
.TP
|
||||
.BR local " \fIVAR\fP[\fB=\fP\fIvalue\fP] ..."
|
||||
In a function: the variable gets its previous value back when the function
|
||||
returns. Without a value it is unset.
|
||||
.TP
|
||||
.BR shift " [\fIn\fP]"
|
||||
Remove the first
|
||||
.I n
|
||||
(default 1) positional parameters.
|
||||
.TP
|
||||
.BR read " [\fB\-r\fP] [\fB\-p\fP \fIprompt\fP] [\fIVAR\fP ...]"
|
||||
Read a line from standard input and split it into fields at the
|
||||
characters of
|
||||
.B IFS
|
||||
(default blank, tab and newline). Each
|
||||
.I VAR
|
||||
gets one field, the last one the rest of the line; without
|
||||
.I VAR
|
||||
the whole line is stored in
|
||||
.BR REPLY .
|
||||
Without
|
||||
.BR \-r ,
|
||||
a backslash escapes the next character and continues the line at its end.
|
||||
.B \-p
|
||||
prints
|
||||
.I prompt
|
||||
if the input is a terminal. The exit status is 1 at the end of the input.
|
||||
.TP
|
||||
.B help
|
||||
Show a summary of builtins and features.
|
||||
.SH JOB CONTROL
|
||||
In interactive shells, each command line runs as a job in its own process
|
||||
group.
|
||||
.B Ctrl+Z
|
||||
stops the foreground job,
|
||||
.B Ctrl+C
|
||||
interrupts it.
|
||||
.BR jobs ,
|
||||
.BR fg ,
|
||||
.B bg
|
||||
and
|
||||
.B wait
|
||||
manage the jobs;
|
||||
.B %n
|
||||
or
|
||||
.I n
|
||||
refers to job
|
||||
.IR n ,
|
||||
.B %\-
|
||||
to the previous job. Finished background jobs are reported before the
|
||||
next prompt. Exiting with stopped jobs warns once.
|
||||
.SH INTERACTIVE USE
|
||||
.TP
|
||||
.B Up/Down
|
||||
Browse the command history.
|
||||
.TP
|
||||
.B Tab
|
||||
Complete commands, aliases and file names.
|
||||
.TP
|
||||
.B Ctrl+C
|
||||
Cancel the current line or command.
|
||||
.TP
|
||||
.B Ctrl+D
|
||||
Exit the shell.
|
||||
.PP
|
||||
Lines starting with a space are not saved in the history.
|
||||
.PP
|
||||
The prompt shows
|
||||
.IR user @ host : dir
|
||||
followed by
|
||||
.BR $ .
|
||||
If the last command failed, its exit status is shown as
|
||||
.BI [ N ]
|
||||
before the
|
||||
.BR $ .
|
||||
.SH ENVIRONMENT
|
||||
.TP
|
||||
.B GOSH_HISTFILE
|
||||
Path of the history file. If set to an empty value, no history is saved.
|
||||
.TP
|
||||
.B XDG_STATE_HOME
|
||||
Base directory of the default history file
|
||||
.IR $XDG_STATE_HOME/gosh/history .
|
||||
.TP
|
||||
.B GOSH_COLORS
|
||||
Prompt colors as colon-separated
|
||||
.IB key = code
|
||||
entries. Keys are
|
||||
.B user
|
||||
(default
|
||||
.BR 1;32 ),
|
||||
.B root
|
||||
.RB ( 1;31 ),
|
||||
.B path
|
||||
.RB ( 1;34 )
|
||||
and
|
||||
.B error
|
||||
.RB ( 1;31 );
|
||||
values are ANSI SGR codes, an empty value disables the color. Example:
|
||||
.B GOSH_COLORS=\(aquser=1;33:path=36\(aq
|
||||
.TP
|
||||
.B NO_COLOR
|
||||
If set, the prompt is not colored. Colors are also disabled with
|
||||
.B TERM=dumb
|
||||
or when the output is not a terminal.
|
||||
.TP
|
||||
.B HOME
|
||||
Used for
|
||||
.B ~
|
||||
and
|
||||
.B cd
|
||||
without argument.
|
||||
.TP
|
||||
.B PATH
|
||||
Directories searched for commands.
|
||||
.TP
|
||||
.B IFS
|
||||
Field separators for
|
||||
.BR read .
|
||||
.SH FILES
|
||||
.TP
|
||||
.I /etc/gosh/profile
|
||||
System-wide profile for login shells.
|
||||
.TP
|
||||
.I ~/.gosh_profile
|
||||
Personal profile for login shells.
|
||||
.TP
|
||||
.I /etc/gosh/goshrc
|
||||
System-wide startup file for interactive shells.
|
||||
.TP
|
||||
.I ~/.goshrc
|
||||
Personal startup file for interactive shells.
|
||||
.TP
|
||||
.I ~/.local/state/gosh/history
|
||||
Default history file (mode 0600).
|
||||
.SH EXIT STATUS
|
||||
The exit status of the last command, or the argument of
|
||||
.BR exit .
|
||||
Typical values:
|
||||
.TP
|
||||
.B 1
|
||||
General error.
|
||||
.TP
|
||||
.B 2
|
||||
Syntax error or invalid option.
|
||||
.TP
|
||||
.B 126
|
||||
Command not executable.
|
||||
.TP
|
||||
.B 127
|
||||
Command not found.
|
||||
.TP
|
||||
.BI 128+ n
|
||||
Command terminated by signal
|
||||
.I n
|
||||
(130 for Ctrl+C).
|
||||
.SH EXAMPLES
|
||||
.nf
|
||||
gosh \-c \(aqcd /srv && git log | head\(aq
|
||||
for f in *.log; do gzip "$f"; done
|
||||
cp config.yaml{,.bak}
|
||||
make > build.log 2>&1 || echo "failed: $?"
|
||||
LANG=C sort file
|
||||
alias ll=\(aqls \-l\(aq
|
||||
greet() { echo "Hello ${1:\-World}"; }
|
||||
git ls\-files | while read \-r f; do wc \-l "$f"; done
|
||||
while read \-r user rest; do echo "$user"; done < /etc/passwd
|
||||
(cd build && make) > build.log 2>&1
|
||||
case "$1" in start|stop) echo "$1ing" ;; *) echo "usage: $0 start|stop" ;; esac
|
||||
read \-r \-p \(aqName? \(aq name
|
||||
chsh \-s /usr/bin/gosh
|
||||
.fi
|
||||
.SH SEE ALSO
|
||||
.BR sh (1),
|
||||
.BR bash (1),
|
||||
.BR chsh (1),
|
||||
.BR shells (5)
|
||||
.SH AUTHOR
|
||||
Florian Walther <florian.walther@certainity.com>
|
||||
@@ -1,8 +1,8 @@
|
||||
package main
|
||||
|
||||
// Parser and executor for command lines and scripts: lists (; & && || and
|
||||
// newlines), pipelines, ! and the control structures if, for, while and
|
||||
// until. Simple commands (with their pipes and redirections) are kept as
|
||||
// newlines), pipelines, ! and the compound commands if, for, while, until,
|
||||
// case, { ...; } and ( ... ), and function definitions. Simple commands (with their pipes and redirections) are kept as
|
||||
// text; they are expanded and run by execCommand only when they are
|
||||
// executed, so that e.g. the variable of a for loop is expanded anew in
|
||||
// every iteration.
|
||||
@@ -11,6 +11,8 @@ import (
|
||||
"errors"
|
||||
"fmt"
|
||||
"os"
|
||||
"path"
|
||||
"slices"
|
||||
"strconv"
|
||||
"strings"
|
||||
"syscall"
|
||||
@@ -48,7 +50,13 @@ var aliasExpansion = true
|
||||
|
||||
// reserved words that end a list; they are only recognized as the first word
|
||||
// of a command.
|
||||
var terminators = map[string]bool{"then": true, "elif": true, "else": true, "fi": true, "do": true, "done": true}
|
||||
var terminators = map[string]bool{
|
||||
"then": true, "elif": true, "else": true, "fi": true, "do": true, "done": true,
|
||||
"esac": true, "}": true,
|
||||
}
|
||||
|
||||
// compoundStarts are the reserved words that start a compound command.
|
||||
var compoundStarts = map[string]bool{"if": true, "for": true, "while": true, "until": true, "case": true, "{": true}
|
||||
|
||||
// ---------------------------------------------------------------------------
|
||||
// Lexer
|
||||
@@ -57,7 +65,7 @@ type tokenKind int
|
||||
|
||||
const (
|
||||
tWord tokenKind = iota
|
||||
tOp // ; & && || | or newline
|
||||
tOp // ; ;; & && || | ( ) or newline
|
||||
)
|
||||
|
||||
type rawToken struct {
|
||||
@@ -126,6 +134,9 @@ func lex(src string) ([]rawToken, error) {
|
||||
switch {
|
||||
case ch == ' ' || ch == '\t':
|
||||
i++
|
||||
case ch == ';' && next == ';':
|
||||
op(";;", i)
|
||||
i += 2
|
||||
case ch == '\n' || ch == ';':
|
||||
op(string(ch), i)
|
||||
i++
|
||||
@@ -137,7 +148,7 @@ func lex(src string) ([]rawToken, error) {
|
||||
case ch == '|' && next == '|', ch == '&' && next == '&':
|
||||
op(src[i:i+2], i)
|
||||
i += 2
|
||||
case ch == '|', ch == '&' && next != '>':
|
||||
case ch == '|', ch == '&' && next != '>', ch == '(', ch == ')':
|
||||
op(string(ch), i)
|
||||
i++
|
||||
default:
|
||||
@@ -167,6 +178,12 @@ func lexWord(src string, i int) (int, error) {
|
||||
return 0, errIncomplete
|
||||
}
|
||||
j++
|
||||
if isSubstStart(src, j) {
|
||||
// \$(...) is literal text, but its ( and ) belong to the word
|
||||
if end := substEnd(src, j); end >= 0 {
|
||||
j = end
|
||||
}
|
||||
}
|
||||
case isSubstStart(src, j):
|
||||
end := substEnd(src, j)
|
||||
if end < 0 {
|
||||
@@ -183,7 +200,7 @@ func lexWord(src string, i int) (int, error) {
|
||||
}
|
||||
case ch == '"' || ch == '\'':
|
||||
quote = ch
|
||||
case ch == ' ' || ch == '\t' || ch == '\n' || ch == ';' || ch == '|':
|
||||
case ch == ' ' || ch == '\t' || ch == '\n' || ch == ';' || ch == '|' || ch == '(' || ch == ')':
|
||||
return j, nil
|
||||
case ch == '&':
|
||||
// &>, >& and <& are redirections, not the & operator
|
||||
@@ -221,6 +238,7 @@ type listEntry struct {
|
||||
type andOrNode struct {
|
||||
first *pipelineNode
|
||||
rest []andOrPart
|
||||
text string // the source, to run it in a subshell in the background
|
||||
}
|
||||
|
||||
type andOrPart struct {
|
||||
@@ -228,8 +246,8 @@ type andOrPart struct {
|
||||
pipeline *pipelineNode
|
||||
}
|
||||
|
||||
// pipelineNode is a simple command (whose text may contain a pipeline) or a
|
||||
// control structure, optionally negated with !.
|
||||
// pipelineNode is a pipeline (a simpleNode or pipeNode) or a single
|
||||
// compound command, optionally negated with !.
|
||||
type pipelineNode struct {
|
||||
negate bool
|
||||
cmd node
|
||||
@@ -240,6 +258,33 @@ type simpleNode struct {
|
||||
text string
|
||||
}
|
||||
|
||||
// pipeNode is a pipeline that contains compound commands. Like all commands
|
||||
// of a pipeline in sh, they run in subshells (new gosh processes), since
|
||||
// the commands of a pipeline run concurrently.
|
||||
type pipeNode struct {
|
||||
elems []pipeElem
|
||||
text string
|
||||
}
|
||||
|
||||
type pipeElem struct {
|
||||
text string // the source of the command, with its redirections
|
||||
compound bool
|
||||
subshell string // for ( list ): the list, which runs in the subshell directly
|
||||
}
|
||||
|
||||
// redirNode is a compound command with redirections; they apply to all
|
||||
// commands in it.
|
||||
type redirNode struct {
|
||||
cmd node
|
||||
redirs string // the source text of the redirections
|
||||
}
|
||||
|
||||
// subshellNode is ( list ): the list runs in a new gosh process, so that it
|
||||
// cannot change the shell.
|
||||
type subshellNode struct {
|
||||
text string // the source of the list
|
||||
}
|
||||
|
||||
type ifNode struct {
|
||||
conds []*listNode
|
||||
bodies []*listNode
|
||||
@@ -259,6 +304,27 @@ type whileNode struct {
|
||||
body *listNode
|
||||
}
|
||||
|
||||
// caseNode is case word in pattern|pattern) list ;; ... esac.
|
||||
type caseNode struct {
|
||||
word string // expanded when the case command runs
|
||||
clauses []caseClause
|
||||
}
|
||||
|
||||
type caseClause struct {
|
||||
patterns []string // expanded when they are tried
|
||||
body *listNode
|
||||
}
|
||||
|
||||
// groupNode is { list; }.
|
||||
type groupNode struct {
|
||||
body *listNode
|
||||
}
|
||||
|
||||
// funcDefNode is a function definition name() compound-command.
|
||||
type funcDefNode struct {
|
||||
def *funcDef
|
||||
}
|
||||
|
||||
// singleSimple returns the simple command if the list is just that.
|
||||
func (l *listNode) singleSimple() *simpleNode {
|
||||
if len(l.items) != 1 || l.items[0].background {
|
||||
@@ -284,6 +350,10 @@ type parser struct {
|
||||
// parse parses a command line or script. It returns errIncomplete if the
|
||||
// input ends inside a construct.
|
||||
func parse(src string) (*listNode, error) {
|
||||
src, err := extractHeredocs(src)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
src, continued := joinContinuationLines(src)
|
||||
if continued {
|
||||
return nil, errIncomplete
|
||||
@@ -356,7 +426,7 @@ func (p *parser) parseList(terms map[string]bool) (*listNode, error) {
|
||||
for {
|
||||
p.skipNewlines()
|
||||
t := p.peek()
|
||||
if t == nil || t.kind == tWord && terms[t.text] {
|
||||
if t == nil || terms[t.text] {
|
||||
return list, nil
|
||||
}
|
||||
ao, err := p.parseAndOr()
|
||||
@@ -371,16 +441,12 @@ func (p *parser) parseList(terms map[string]bool) (*listNode, error) {
|
||||
case t.kind == tOp && (t.text == ";" || t.text == "&" || t.text == "\n"):
|
||||
p.pos++
|
||||
entry.background = t.text == "&"
|
||||
case t.kind == tWord && terms[t.text]:
|
||||
// e.g. "fi" right after the end of a nested control structure
|
||||
case terms[t.text]:
|
||||
// e.g. "fi" right after the end of a nested control structure,
|
||||
// or ;; after a command in a case clause
|
||||
default:
|
||||
return nil, p.unexpected(t)
|
||||
}
|
||||
if entry.background {
|
||||
if _, ok := ao.first.cmd.(*simpleNode); !ok || len(ao.rest) > 0 || ao.first.negate {
|
||||
return nil, errors.New("only simple commands and pipelines can run in the background")
|
||||
}
|
||||
}
|
||||
list.items = append(list.items, entry)
|
||||
}
|
||||
}
|
||||
@@ -397,6 +463,7 @@ func (p *parser) nonEmpty(list *listNode) error {
|
||||
}
|
||||
|
||||
func (p *parser) parseAndOr() (*andOrNode, error) {
|
||||
start := p.peek().start
|
||||
first, err := p.parsePipeline()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
@@ -405,6 +472,7 @@ func (p *parser) parseAndOr() (*andOrNode, error) {
|
||||
for {
|
||||
t := p.peek()
|
||||
if t == nil || t.kind != tOp || (t.text != "&&" && t.text != "||") {
|
||||
ao.text = p.src[start:p.toks[p.pos-1].end]
|
||||
return ao, nil
|
||||
}
|
||||
p.pos++
|
||||
@@ -420,79 +488,188 @@ func (p *parser) parseAndOr() (*andOrNode, error) {
|
||||
}
|
||||
}
|
||||
|
||||
// parsePipeline parses [!] command [| command]... A pipeline of simple
|
||||
// commands stays one simpleNode (its text is split into the commands when it
|
||||
// runs); a pipeline with compound commands becomes a pipeNode.
|
||||
func (p *parser) parsePipeline() (*pipelineNode, error) {
|
||||
pl := &pipelineNode{}
|
||||
if p.peekWord("!") {
|
||||
pl.negate = true
|
||||
p.pos++
|
||||
}
|
||||
var (
|
||||
elems []pipeElem
|
||||
cmds []node
|
||||
start = -1
|
||||
)
|
||||
for {
|
||||
t := p.peek()
|
||||
if t == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
if t.kind == tOp || terminators[t.text] {
|
||||
if t.kind == tOp && t.text != "(" || t.kind == tWord && terminators[t.text] {
|
||||
return nil, p.unexpected(t)
|
||||
}
|
||||
|
||||
var err error
|
||||
compound := true
|
||||
switch t.text {
|
||||
case "if":
|
||||
pl.cmd, err = p.parseIf()
|
||||
case "for":
|
||||
pl.cmd, err = p.parseFor()
|
||||
case "while", "until":
|
||||
pl.cmd, err = p.parseWhile()
|
||||
default:
|
||||
compound = false
|
||||
pl.cmd, err = p.parseSimple()
|
||||
if start < 0 {
|
||||
start = t.start
|
||||
}
|
||||
cmd, compound, err := p.parseCommand()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
elem := pipeElem{text: p.src[t.start:p.toks[p.pos-1].end], compound: compound}
|
||||
if sub, ok := cmd.(*subshellNode); ok {
|
||||
elem.subshell = sub.text
|
||||
}
|
||||
elems = append(elems, elem)
|
||||
cmds = append(cmds, cmd)
|
||||
|
||||
if compound {
|
||||
if t := p.peek(); t != nil {
|
||||
if t := p.peek(); t == nil || t.kind != tOp || t.text != "|" {
|
||||
break
|
||||
}
|
||||
p.pos++
|
||||
p.skipNewlines()
|
||||
if p.peek() == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
}
|
||||
|
||||
text := p.src[start:p.toks[p.pos-1].end]
|
||||
compound := false
|
||||
for i, e := range elems {
|
||||
if _, ok := cmds[i].(*funcDefNode); ok && len(elems) > 1 {
|
||||
return nil, errors.New("function definitions in pipelines are not supported")
|
||||
}
|
||||
compound = compound || e.compound
|
||||
}
|
||||
switch {
|
||||
case t.kind == tOp && t.text == "|":
|
||||
return nil, errors.New("control structures in pipelines are not supported")
|
||||
case t.kind == tWord && !terminators[t.text]:
|
||||
return nil, fmt.Errorf("redirections of control structures are not supported (near `%s')", t.text)
|
||||
}
|
||||
}
|
||||
case len(elems) == 1:
|
||||
pl.cmd = cmds[0]
|
||||
case !compound:
|
||||
pl.cmd = &simpleNode{text: text}
|
||||
default:
|
||||
pl.cmd = &pipeNode{elems: elems, text: text}
|
||||
}
|
||||
return pl, nil
|
||||
}
|
||||
|
||||
// parseSimple parses a pipeline of simple commands and returns its text.
|
||||
// parseCommand parses a simple command, a compound command with its
|
||||
// redirections or a function definition, and reports whether it is not a
|
||||
// simple command.
|
||||
func (p *parser) parseCommand() (node, bool, error) {
|
||||
t := p.peek()
|
||||
start := t.start
|
||||
if name, ok := p.funcDefName(); ok {
|
||||
def, err := p.parseFuncDef(name, start)
|
||||
if err != nil {
|
||||
return nil, true, err
|
||||
}
|
||||
if t := p.peek(); t != nil && t.kind == tWord && !terminators[t.text] {
|
||||
return nil, true, errors.New("redirections of function definitions are not supported")
|
||||
}
|
||||
return def, true, nil
|
||||
}
|
||||
if !isCompoundStart(t) {
|
||||
cmd, err := p.parseSimple()
|
||||
return cmd, false, err
|
||||
}
|
||||
cmd, err := p.parseCompound()
|
||||
if err != nil {
|
||||
return nil, true, err
|
||||
}
|
||||
redirs, err := p.parseRedirections()
|
||||
if err != nil {
|
||||
return nil, true, err
|
||||
}
|
||||
if redirs != "" {
|
||||
cmd = &redirNode{cmd: cmd, redirs: redirs}
|
||||
}
|
||||
return cmd, true, nil
|
||||
}
|
||||
|
||||
// isCompoundStart reports whether a compound command starts at t.
|
||||
func isCompoundStart(t *rawToken) bool {
|
||||
return t.kind == tWord && compoundStarts[t.text] || t.kind == tOp && t.text == "("
|
||||
}
|
||||
|
||||
// parseRedirections parses the redirections after a compound command and
|
||||
// returns their source text (expanded when the command runs).
|
||||
func (p *parser) parseRedirections() (string, error) {
|
||||
start, end := -1, -1
|
||||
for t := p.peek(); t != nil && t.kind == tWord && !terminators[t.text]; t = p.peek() {
|
||||
needsTarget, ok := redirectionWord(t.text)
|
||||
if !ok {
|
||||
return "", syntaxError(t.text)
|
||||
}
|
||||
if start < 0 {
|
||||
start = t.start
|
||||
}
|
||||
end = t.end
|
||||
p.pos++
|
||||
if needsTarget {
|
||||
t = p.peek()
|
||||
if t == nil || t.kind != tWord {
|
||||
if t == nil {
|
||||
return "", syntaxError("newline")
|
||||
}
|
||||
return "", p.unexpected(t)
|
||||
}
|
||||
end = t.end
|
||||
p.pos++
|
||||
}
|
||||
}
|
||||
if start < 0 {
|
||||
return "", nil
|
||||
}
|
||||
return p.src[start:end], nil
|
||||
}
|
||||
|
||||
// redirectionWord reports whether word starts with a redirection operator
|
||||
// (optionally after a file descriptor), and whether the target is the next
|
||||
// word (2> file instead of 2>file).
|
||||
func redirectionWord(word string) (needsTarget, ok bool) {
|
||||
w := strings.TrimLeft(word, "0123456789")
|
||||
for _, op := range []string{"&>>", "&>", "<<<", ">>", ">&", "<&", ">", "<"} {
|
||||
if strings.HasPrefix(w, op) {
|
||||
if op[0] == '&' && len(w) != len(word) {
|
||||
return false, false
|
||||
}
|
||||
return w == op, true
|
||||
}
|
||||
}
|
||||
return false, false
|
||||
}
|
||||
|
||||
// parseSimple parses a simple command (without pipes) and returns its text.
|
||||
func (p *parser) parseSimple() (*simpleNode, error) {
|
||||
start := p.toks[p.pos].start
|
||||
end := start
|
||||
for t := p.peek(); t != nil; t = p.peek() {
|
||||
if t.kind == tWord {
|
||||
for t := p.peek(); t != nil && t.kind == tWord; t = p.peek() {
|
||||
end = t.end
|
||||
p.pos++
|
||||
continue
|
||||
}
|
||||
if t.text != "|" {
|
||||
break
|
||||
}
|
||||
p.pos++
|
||||
end = t.end
|
||||
p.skipNewlines()
|
||||
next := p.peek()
|
||||
switch {
|
||||
case next == nil:
|
||||
return nil, errIncomplete
|
||||
case next.kind == tOp || terminators[next.text]:
|
||||
return nil, p.unexpected(next)
|
||||
case next.text == "if" || next.text == "for" || next.text == "while" || next.text == "until":
|
||||
return nil, errors.New("control structures in pipelines are not supported")
|
||||
}
|
||||
}
|
||||
return &simpleNode{text: p.src[start:end]}, nil
|
||||
}
|
||||
|
||||
// parseCompound parses the compound command that starts at the current
|
||||
// token.
|
||||
func (p *parser) parseCompound() (node, error) {
|
||||
switch p.peek().text {
|
||||
case "if":
|
||||
return p.parseIf()
|
||||
case "for":
|
||||
return p.parseFor()
|
||||
case "while", "until":
|
||||
return p.parseWhile()
|
||||
case "case":
|
||||
return p.parseCase()
|
||||
case "(":
|
||||
return p.parseSubshell()
|
||||
default: // {
|
||||
return p.parseGroup()
|
||||
}
|
||||
}
|
||||
|
||||
func (p *parser) parseIf() (*ifNode, error) {
|
||||
p.pos++ // if
|
||||
n := &ifNode{}
|
||||
@@ -604,6 +781,167 @@ func (p *parser) parseWhile() (*whileNode, error) {
|
||||
return n, nil
|
||||
}
|
||||
|
||||
// parseGroup parses { list; }.
|
||||
func (p *parser) parseGroup() (*groupNode, error) {
|
||||
p.pos++ // {
|
||||
body, err := p.parseList(map[string]bool{"}": true})
|
||||
if err == nil {
|
||||
err = p.nonEmpty(body)
|
||||
}
|
||||
if err == nil {
|
||||
err = p.expect("}")
|
||||
}
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &groupNode{body: body}, nil
|
||||
}
|
||||
|
||||
// parseSubshell parses ( list ).
|
||||
func (p *parser) parseSubshell() (*subshellNode, error) {
|
||||
p.pos++ // (
|
||||
start := p.toks[p.pos-1].end
|
||||
body, err := p.parseList(map[string]bool{")": true})
|
||||
if err == nil {
|
||||
err = p.nonEmpty(body)
|
||||
}
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
t := p.peek()
|
||||
if t == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
if t.kind != tOp || t.text != ")" {
|
||||
return nil, p.unexpected(t)
|
||||
}
|
||||
p.pos++
|
||||
return &subshellNode{text: p.src[start:t.start]}, nil
|
||||
}
|
||||
|
||||
// parseCase parses case word in [(]pattern[|pattern]...) list ;; ... esac.
|
||||
// The last clause may omit the ;;.
|
||||
func (p *parser) parseCase() (*caseNode, error) {
|
||||
p.pos++ // case
|
||||
t := p.peek()
|
||||
if t == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
if t.kind != tWord {
|
||||
return nil, p.unexpected(t)
|
||||
}
|
||||
n := &caseNode{word: t.text}
|
||||
p.pos++
|
||||
p.skipNewlines()
|
||||
if err := p.expect("in"); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
for {
|
||||
p.skipNewlines()
|
||||
t := p.peek()
|
||||
if t == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
if t.kind == tWord && t.text == "esac" {
|
||||
p.pos++
|
||||
return n, nil
|
||||
}
|
||||
patterns, err := p.parsePatterns()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
body, err := p.parseList(map[string]bool{";;": true, "esac": true})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
n.clauses = append(n.clauses, caseClause{patterns: patterns, body: body})
|
||||
if t := p.peek(); t == nil {
|
||||
return nil, errIncomplete
|
||||
} else if t.text == ";;" {
|
||||
p.pos++
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// parsePatterns parses the patterns of a case clause up to and including the
|
||||
// ).
|
||||
func (p *parser) parsePatterns() ([]string, error) {
|
||||
if t := p.peek(); t.kind == tOp && t.text == "(" {
|
||||
p.pos++ // the optional ( before the first pattern
|
||||
}
|
||||
var patterns []string
|
||||
for {
|
||||
t := p.peek()
|
||||
if t == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
if t.kind != tWord {
|
||||
return nil, p.unexpected(t)
|
||||
}
|
||||
patterns = append(patterns, t.text)
|
||||
p.pos++
|
||||
t = p.peek()
|
||||
switch {
|
||||
case t == nil:
|
||||
return nil, errIncomplete
|
||||
case t.kind == tOp && t.text == "|":
|
||||
p.pos++
|
||||
case t.kind == tOp && t.text == ")":
|
||||
p.pos++
|
||||
return patterns, nil
|
||||
default:
|
||||
return nil, p.unexpected(t)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// funcDefName reports whether a function definition starts at the current
|
||||
// token: name(), or function name [()]. It consumes the tokens up to the
|
||||
// body.
|
||||
func (p *parser) funcDefName() (string, bool) {
|
||||
start := p.pos
|
||||
if t := p.peek(); t.kind != tWord {
|
||||
return "", false
|
||||
} else if t.text == "function" {
|
||||
p.pos++
|
||||
if t := p.peek(); t == nil || t.kind != tWord || !isFuncName(t.text) {
|
||||
p.pos = start
|
||||
return "", false
|
||||
}
|
||||
}
|
||||
name := p.peek().text
|
||||
isOp := func(i int, text string) bool {
|
||||
return i < len(p.toks) && p.toks[i].kind == tOp && p.toks[i].text == text
|
||||
}
|
||||
switch {
|
||||
case isOp(p.pos+1, "(") && isOp(p.pos+2, ")") && isFuncName(name):
|
||||
p.pos += 3
|
||||
case p.pos > start:
|
||||
p.pos++ // function name
|
||||
default:
|
||||
return "", false
|
||||
}
|
||||
return name, true
|
||||
}
|
||||
|
||||
// parseFuncDef parses the body of a function definition that started at
|
||||
// src[start]: a compound command.
|
||||
func (p *parser) parseFuncDef(name string, start int) (*funcDefNode, error) {
|
||||
p.skipNewlines()
|
||||
t := p.peek()
|
||||
if t == nil {
|
||||
return nil, errIncomplete
|
||||
}
|
||||
if !isCompoundStart(t) {
|
||||
return nil, fmt.Errorf("%s: the body of a function must be a compound command like { ...; }", sanitize(name))
|
||||
}
|
||||
body, err := p.parseCompound()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &funcDefNode{def: &funcDef{name: name, body: body, text: p.src[start:p.toks[p.pos-1].end]}}, nil
|
||||
}
|
||||
|
||||
// parseLoopBody parses "do list done".
|
||||
func (p *parser) parseLoopBody() (*listNode, error) {
|
||||
if err := p.expect("do"); err != nil {
|
||||
@@ -623,11 +961,14 @@ func (p *parser) parseLoopBody() (*listNode, error) {
|
||||
// Execution
|
||||
|
||||
// isAbort reports whether err stops the execution of the enclosing lists:
|
||||
// break, continue, or a command that was interrupted with Ctrl+C (like in
|
||||
// bash, Ctrl+C aborts the whole command line, e.g. a loop).
|
||||
// break, continue, return, or a command that was interrupted with Ctrl+C
|
||||
// (like in bash, Ctrl+C aborts the whole command line, e.g. a loop).
|
||||
func isAbort(err error) bool {
|
||||
var lc loopControl
|
||||
return errors.As(err, &lc) || exitStatus(err) == 128+int(syscall.SIGINT)
|
||||
var (
|
||||
lc loopControl
|
||||
ret returnSignal
|
||||
)
|
||||
return errors.As(err, &lc) || errors.As(err, &ret) || exitStatus(err) == 128+int(syscall.SIGINT)
|
||||
}
|
||||
|
||||
// silent returns an error with only the exit status of err, for errors that
|
||||
@@ -644,7 +985,7 @@ func (l *listNode) exec() error {
|
||||
for _, entry := range l.items {
|
||||
printError(err)
|
||||
if entry.background {
|
||||
err = entry.andOr.first.cmd.(*simpleNode).run(true)
|
||||
err = entry.andOr.runBackground()
|
||||
} else {
|
||||
err = entry.andOr.exec()
|
||||
}
|
||||
@@ -672,6 +1013,22 @@ func (a *andOrNode) exec() error {
|
||||
return err
|
||||
}
|
||||
|
||||
// runBackground starts the and-or list as a background job. Pipelines run
|
||||
// like in the foreground, everything else in a subshell.
|
||||
func (a *andOrNode) runBackground() error {
|
||||
if len(a.rest) == 0 && !a.first.negate {
|
||||
switch cmd := a.first.cmd.(type) {
|
||||
case *simpleNode:
|
||||
return cmd.run(true)
|
||||
case *pipeNode:
|
||||
return cmd.run(true)
|
||||
case *subshellNode:
|
||||
return runPipeline([]stage{{script: cmd.text}}, a.text, true)
|
||||
}
|
||||
}
|
||||
return runPipeline([]stage{{script: a.text}}, a.text, true)
|
||||
}
|
||||
|
||||
func (pl *pipelineNode) exec() error {
|
||||
err := pl.cmd.exec()
|
||||
if !pl.negate || isAbort(err) {
|
||||
@@ -779,7 +1136,8 @@ func (n *whileNode) exec() error {
|
||||
}
|
||||
|
||||
func (n *forNode) exec() error {
|
||||
var words []string
|
||||
// Without "in", the loop runs over the positional parameters
|
||||
words := slices.Clone(positional)
|
||||
if n.hasIn {
|
||||
var err error
|
||||
if words, err = expandWordList(n.words); err != nil {
|
||||
@@ -804,6 +1162,144 @@ func (n *forNode) exec() error {
|
||||
return result
|
||||
}
|
||||
|
||||
func (n *groupNode) exec() error {
|
||||
return n.body.exec()
|
||||
}
|
||||
|
||||
func (n *subshellNode) exec() error {
|
||||
return runPipeline([]stage{{script: n.text}}, "("+strings.TrimSpace(n.text)+")", false)
|
||||
}
|
||||
|
||||
// exec runs the compound command with stdin, stdout and stderr of the shell
|
||||
// redirected.
|
||||
func (n *redirNode) exec() error {
|
||||
fds, opened, err := openRedirections(n.redirs)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
saved := ioOverride
|
||||
ioOverride = fds
|
||||
defer func() {
|
||||
ioOverride = saved
|
||||
for _, f := range opened {
|
||||
f.Close()
|
||||
}
|
||||
}()
|
||||
return n.cmd.exec()
|
||||
}
|
||||
|
||||
func (n *pipeNode) exec() error {
|
||||
return n.run(false)
|
||||
}
|
||||
|
||||
// run builds the stages of the pipeline: simple commands are expanded,
|
||||
// compound commands run in subshells.
|
||||
func (n *pipeNode) run(background bool) error {
|
||||
substStatus = 0
|
||||
var stages []stage
|
||||
for _, e := range n.elems {
|
||||
switch {
|
||||
case e.subshell != "":
|
||||
stages = append(stages, stage{script: e.subshell})
|
||||
case e.compound:
|
||||
stages = append(stages, stage{script: e.text})
|
||||
default:
|
||||
text := e.text
|
||||
if interactiveShell && aliasExpansion {
|
||||
if tree, err := parse(expandAliases(text)); err == nil {
|
||||
if simple := tree.singleSimple(); simple != nil {
|
||||
text = simple.text
|
||||
}
|
||||
}
|
||||
}
|
||||
st, err := expandStages(text)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if len(st) == 0 {
|
||||
st = []stage{{}}
|
||||
}
|
||||
stages = append(stages, st...)
|
||||
}
|
||||
}
|
||||
return runPipeline(stages, n.text, background)
|
||||
}
|
||||
|
||||
func (n *funcDefNode) exec() error {
|
||||
defineFunction(n.def)
|
||||
return nil
|
||||
}
|
||||
|
||||
// exec runs the body of the first clause with a pattern that matches the
|
||||
// word. The status is 0 if no pattern matches.
|
||||
func (n *caseNode) exec() error {
|
||||
word, err := expandCaseWord(n.word)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
for _, clause := range n.clauses {
|
||||
for _, pattern := range clause.patterns {
|
||||
ok, err := caseMatch(pattern, word)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if ok {
|
||||
return clause.body.exec()
|
||||
}
|
||||
}
|
||||
}
|
||||
lastStatus = 0
|
||||
return nil
|
||||
}
|
||||
|
||||
// expandCaseWord expands the word of a case command: like an argument, but
|
||||
// without brace expansion, wildcards and splitting.
|
||||
func expandCaseWord(text string) (string, error) {
|
||||
tokens, err := tokenize(text)
|
||||
if err != nil {
|
||||
return "", fmt.Errorf("invalid input: %w", err)
|
||||
}
|
||||
var words []string
|
||||
for _, t := range tokens {
|
||||
if t.op != "" {
|
||||
return "", syntaxError(t.op)
|
||||
}
|
||||
words = append(words, t.word)
|
||||
}
|
||||
return strings.Join(words, " "), nil
|
||||
}
|
||||
|
||||
// caseMatch reports whether word matches the pattern of a case clause. The
|
||||
// pattern is expanded first; quoted characters in it match literally. Unlike
|
||||
// for file names, * and ? also match a /.
|
||||
func caseMatch(pattern, word string) (bool, error) {
|
||||
tokens, err := tokenize(pattern)
|
||||
if err != nil {
|
||||
return false, fmt.Errorf("invalid input: %w", err)
|
||||
}
|
||||
var literal, glob []string
|
||||
isGlob := false
|
||||
for _, t := range tokens {
|
||||
if t.op != "" {
|
||||
return false, syntaxError(t.op)
|
||||
}
|
||||
literal = append(literal, t.word)
|
||||
glob = append(glob, t.pattern)
|
||||
isGlob = isGlob || t.glob
|
||||
}
|
||||
if !isGlob {
|
||||
return word == strings.Join(literal, " "), nil
|
||||
}
|
||||
// path.Match does not let * match a /; NUL can be in neither string
|
||||
toNUL := strings.NewReplacer("/", "\x00")
|
||||
ok, err := path.Match(toNUL.Replace(strings.Join(glob, " ")), toNUL.Replace(word))
|
||||
if err != nil {
|
||||
// An invalid pattern only matches itself
|
||||
return word == strings.Join(literal, " "), nil
|
||||
}
|
||||
return ok, nil
|
||||
}
|
||||
|
||||
// expandWordList expands the words of a for loop like the arguments of a
|
||||
// command (braces, ~, variables, $(...), wildcards).
|
||||
func expandWordList(text string) ([]string, error) {
|
||||
|
||||
@@ -0,0 +1,215 @@
|
||||
package main
|
||||
|
||||
// The read builtin: read [-r] [-p prompt] [name ...] reads a line and splits
|
||||
// it into fields at the characters of $IFS (default: blank, tab, newline).
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"fmt"
|
||||
"io"
|
||||
"os"
|
||||
"os/signal"
|
||||
"strings"
|
||||
"syscall"
|
||||
|
||||
"github.com/chzyer/readline"
|
||||
"golang.org/x/sys/unix"
|
||||
)
|
||||
|
||||
// builtinRead implements read. Each name gets one field, the last one the
|
||||
// rest of the line; without names the whole line is stored in $REPLY. The
|
||||
// status is 1 at the end of the input.
|
||||
func builtinRead(args []string, stdin *os.File) error {
|
||||
raw := false
|
||||
prompt := ""
|
||||
args = args[1:]
|
||||
for len(args) > 0 && strings.HasPrefix(args[0], "-") && args[0] != "-" {
|
||||
opt := args[0]
|
||||
args = args[1:]
|
||||
if opt == "--" {
|
||||
break
|
||||
}
|
||||
for k := 1; k < len(opt); k++ {
|
||||
switch opt[k] {
|
||||
case 'r':
|
||||
raw = true
|
||||
case 'p':
|
||||
switch {
|
||||
case k+1 < len(opt):
|
||||
prompt = opt[k+1:]
|
||||
case len(args) > 0:
|
||||
prompt, args = args[0], args[1:]
|
||||
default:
|
||||
return errors.New("read: -p: option requires an argument")
|
||||
}
|
||||
k = len(opt)
|
||||
default:
|
||||
return fmt.Errorf("read: -%c: invalid option\nusage: read [-r] [-p prompt] [name ...]", opt[k])
|
||||
}
|
||||
}
|
||||
}
|
||||
for _, name := range args {
|
||||
if !isVarName(name) {
|
||||
return fmt.Errorf("read: `%s': not a valid identifier", sanitize(name))
|
||||
}
|
||||
}
|
||||
|
||||
terminal := readline.IsTerminal(int(stdin.Fd()))
|
||||
if prompt != "" && terminal {
|
||||
fmt.Fprint(stdio(2), prompt)
|
||||
}
|
||||
line, literal, eof, err := readInputLine(stdin, raw, interactiveShell && terminal)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if len(args) == 0 {
|
||||
os.Setenv("REPLY", line)
|
||||
} else {
|
||||
ifs, ok := os.LookupEnv("IFS")
|
||||
if !ok {
|
||||
ifs = " \t\n"
|
||||
}
|
||||
fields := splitFields(line, literal, ifs, len(args))
|
||||
for i, name := range args {
|
||||
value := ""
|
||||
if i < len(fields) {
|
||||
value = fields[i]
|
||||
}
|
||||
os.Setenv(name, value)
|
||||
}
|
||||
}
|
||||
if eof {
|
||||
return statusError(1)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// readInputLine reads a line from f, byte by byte so that nothing after the
|
||||
// line is consumed. Unless raw is set, a backslash escapes the next
|
||||
// character (literal marks the escaped characters, which never split
|
||||
// fields) and backslash-newline continues the line. eof reports that the
|
||||
// input ended before a newline. If interruptible is set, Ctrl+C aborts the
|
||||
// read with status 130.
|
||||
func readInputLine(f *os.File, raw, interruptible bool) (line string, literal []bool, eof bool, err error) {
|
||||
readByte := plainByteReader(f)
|
||||
if interruptible {
|
||||
intr := make(chan os.Signal, 1)
|
||||
signal.Notify(intr, os.Interrupt)
|
||||
defer signal.Stop(intr)
|
||||
readByte = interruptibleByteReader(f, intr)
|
||||
}
|
||||
|
||||
var b []byte
|
||||
for {
|
||||
c, err := readByte()
|
||||
if err == io.EOF {
|
||||
return string(b), literal, true, nil
|
||||
}
|
||||
if err != nil {
|
||||
return "", nil, false, err
|
||||
}
|
||||
if c == '\n' {
|
||||
return string(b), literal, false, nil
|
||||
}
|
||||
if c == '\\' && !raw {
|
||||
c, err = readByte()
|
||||
if err == io.EOF {
|
||||
return string(b), literal, true, nil
|
||||
}
|
||||
if err != nil {
|
||||
return "", nil, false, err
|
||||
}
|
||||
if c == '\n' {
|
||||
continue // the line goes on
|
||||
}
|
||||
b = append(b, c)
|
||||
literal = append(literal, true)
|
||||
continue
|
||||
}
|
||||
b = append(b, c)
|
||||
literal = append(literal, false)
|
||||
}
|
||||
}
|
||||
|
||||
func plainByteReader(f *os.File) func() (byte, error) {
|
||||
buf := make([]byte, 1)
|
||||
return func() (byte, error) {
|
||||
for {
|
||||
n, err := f.Read(buf)
|
||||
if n == 1 {
|
||||
return buf[0], nil
|
||||
}
|
||||
if err != nil {
|
||||
return 0, err
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// interruptibleByteReader reads from the terminal f only when input is
|
||||
// available, so that a SIGINT on intr can end the read in between.
|
||||
func interruptibleByteReader(f *os.File, intr chan os.Signal) func() (byte, error) {
|
||||
next := plainByteReader(f)
|
||||
fds := []unix.PollFd{{Fd: int32(f.Fd()), Events: unix.POLLIN}}
|
||||
return func() (byte, error) {
|
||||
for {
|
||||
select {
|
||||
case <-intr:
|
||||
fmt.Fprintln(stdio(2))
|
||||
return 0, statusError(128 + int(syscall.SIGINT))
|
||||
default:
|
||||
}
|
||||
n, err := unix.Poll(fds, 100)
|
||||
if err != nil && !errors.Is(err, unix.EINTR) {
|
||||
return 0, err
|
||||
}
|
||||
if n > 0 {
|
||||
return next()
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// splitFields splits line into at most n fields like read does: IFS
|
||||
// whitespace (blank, tab, newline in ifs) around fields is removed, other IFS
|
||||
// characters separate fields (also empty ones). The last field is the rest of
|
||||
// the line. Characters marked in literal are never separators.
|
||||
func splitFields(line string, literal []bool, ifs string, n int) []string {
|
||||
isSep := func(i int) bool { return !literal[i] && strings.IndexByte(ifs, line[i]) >= 0 }
|
||||
isSpace := func(i int) bool { return isSep(i) && strings.IndexByte(" \t\n", line[i]) >= 0 }
|
||||
|
||||
start, end := 0, len(line)
|
||||
for start < end && isSpace(start) {
|
||||
start++
|
||||
}
|
||||
for end > start && isSpace(end-1) {
|
||||
end--
|
||||
}
|
||||
|
||||
var fields []string
|
||||
i := start
|
||||
for i < end && len(fields) < n-1 {
|
||||
j := i
|
||||
for j < end && !isSep(j) {
|
||||
j++
|
||||
}
|
||||
fields = append(fields, line[i:j])
|
||||
// The separator: whitespace, at most one other IFS character,
|
||||
// whitespace
|
||||
for j < end && isSpace(j) {
|
||||
j++
|
||||
}
|
||||
if j < end && isSep(j) && !isSpace(j) {
|
||||
j++
|
||||
for j < end && isSpace(j) {
|
||||
j++
|
||||
}
|
||||
}
|
||||
i = j
|
||||
}
|
||||
if i < end {
|
||||
fields = append(fields, line[i:end])
|
||||
}
|
||||
return fields
|
||||
}
|
||||
@@ -2,7 +2,8 @@ package main
|
||||
|
||||
// Command substitution: $(command) is replaced by the output of command,
|
||||
// which runs in a subshell (a new gosh process), so that cd, set etc. in it
|
||||
// do not change the shell.
|
||||
// do not change the shell. Functions also run in a subshell in pipelines and
|
||||
// in the background.
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
@@ -67,24 +68,34 @@ func substEnd(s string, i int) int {
|
||||
return -1
|
||||
}
|
||||
|
||||
// subshellCommand returns a command that runs script in a new gosh process
|
||||
// with the same $0, the given positional parameters and the functions of the
|
||||
// shell. (Variables need not be passed: they are all in the environment.)
|
||||
func subshellCommand(script string, params []string) (*exec.Cmd, error) {
|
||||
path := subshellPath
|
||||
if path == "" {
|
||||
var err error
|
||||
if path, err = os.Executable(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
args := append([]string{"-c", functionDefs() + script, scriptName}, params...)
|
||||
return exec.Command(path, args...), nil
|
||||
}
|
||||
|
||||
// commandSubst runs command in a subshell and returns its output without
|
||||
// trailing newlines. stdin and stderr are those of the shell.
|
||||
func commandSubst(command string) (string, error) {
|
||||
if strings.HasPrefix(command, "(") {
|
||||
return "", errors.New("arithmetic expansion $((...)) is not supported")
|
||||
}
|
||||
path := subshellPath
|
||||
if path == "" {
|
||||
var err error
|
||||
if path, err = os.Executable(); err != nil {
|
||||
var out bytes.Buffer
|
||||
cmd, err := subshellCommand(command, positional)
|
||||
if err != nil {
|
||||
return "", err
|
||||
}
|
||||
}
|
||||
|
||||
var out bytes.Buffer
|
||||
cmd := exec.Command(path, "-c", command)
|
||||
cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, &out, os.Stderr
|
||||
err := cmd.Run()
|
||||
cmd.Stdin, cmd.Stdout, cmd.Stderr = stdio(0), &out, stdio(2)
|
||||
err = cmd.Run()
|
||||
substStatus = exitStatus(err)
|
||||
if substStatus == 128+int(syscall.SIGINT) {
|
||||
// Ctrl+C aborts the whole command, like in bash
|
||||
|
||||
Reference in new issue
Block a user