add job control

- in an interactive shell every pipeline runs in its own process group
  and gets the terminal while it runs in the foreground
- Ctrl+Z stops the foreground job, command & starts a job in the
  background; finished and stopped jobs are reported before the prompt
- new builtins jobs, fg, bg and wait (wait also works without job
  control, e.g. in scripts, where background jobs read from /dev/null)
- terminal modes are saved and restored when a job stops or continues
- exit and Ctrl+D warn once if there are stopped jobs
- processes are waited for with wait4 (WUNTRACED) instead of exec.Cmd.Wait
- pty based test for job control (Linux)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.goreleaser.yaml

@@ -22,7 +22,7 @@ builds:
     flags:
       - -trimpath
     ldflags:
-      - -s -w -X main.version={{ .Version }}
+      - -s -w -X main.version={{ .Version }} -X main.commit={{ .ShortCommit }} -X main.branch={{ .Branch }}
     goos:
       - linux
       - darwin

README.md

@@ -2,15 +2,21 @@
 
 ```
 gosh - Go Shell
+Version: 0.2.1 (branch: main, commit: 03e791c)
 
 Built-in commands:
   cd [dir]       - Change directory (cd with no args goes to home)
   pwd           - Print working directory
   echo [args]   - Echo arguments
-  exit [code]   - Exit shell with optional status code
-  quit [code]   - Quit shell with optional status code
+  exit [code]   - Exit shell with status code (default: $?)
+  quit [code]   - Quit shell with status code (default: $?)
   set VAR=val   - Set environment variable
   export VAR=val - Export environment variable
+  source file   - 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
+  wait [%n]     - Wait for job n or all background jobs
   help          - Show this help
 
 Features:
@@ -22,11 +28,253 @@ Features:
     override with $GOSH_HISTFILE); lines starting with a space are not saved
   - Tab completion for commands and file paths
   - Tilde expansion (~, ~/path) at the start of unquoted words
+  - Wildcards: * ? [abc] [a-z] [!abc] match file names (not hidden files
+    unless the pattern starts with a dot); quoted wildcards and values of
+    variables are not expanded, a pattern without match is kept as is
+  - Colored prompt (user@host green, red for root; directory blue),
+    configurable with $GOSH_COLORS, e.g. GOSH_COLORS='user=1;33:path=36'
+    (keys user, root, path; values are ANSI SGR codes, empty = no color);
+    disabled with $NO_COLOR, TERM=dumb or when output is not a terminal
   - Environment variable expansion ($VAR, ${VAR}, ${VAR:-default});
     using an unset variable is an error, use ${VAR:-} for an empty default
+  - Command lists: a ; b (run both), a && b (b only if a succeeded),
+    a || b (b only if a failed); $? is the exit status of the last command
+  - Pipes (a | b) and redirections: < file, > file, >> file, 2> file,
+    2>> file, 2>&1, >&2, &> file (stdout and stderr), &>> file
+  - Job control: command & runs in the background, Ctrl+Z stops the
+    foreground job; jobs, fg, bg and wait manage the jobs
+  - Non-interactive use: gosh -c 'command', gosh script, command | gosh;
+    the exit status is the one of the last command
+  - Startup files: login shells (-l or argv[0] starting with -) read
+    /etc/gosh/profile and ~/.gosh_profile, interactive shells read
+    /etc/gosh/goshrc and ~/.goshrc (skip with --noprofile, --norc)
 
 ```
 
+### Aufruf
+
+```
+gosh [-l] [-i] [--norc] [--noprofile] [script]
+gosh [-l] [--noprofile] -c command
+gosh -version
+```
+
+| Aufruf                 | Verhalten                                                        |
+|------------------------|------------------------------------------------------------------|
+| `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                             |
+| `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)              |
+| `--norc`               | `goshrc`-Dateien nicht lesen                                     |
+| `--noprofile`          | `profile`-Dateien nicht lesen                                    |
+
+Ohne Terminal bricht gosh bei einem fehlgeschlagenen Befehl nicht ab und beendet sich mit dem Exit-Status des letzten Befehls: `127`, wenn ein Befehl nicht gefunden wurde, `126`, wenn er nicht ausführbar ist, `128+n`, wenn er durch Signal `n` beendet wurde. Leere Zeilen und Zeilen, die mit `#` beginnen, werden übersprungen, Skripte können also mit `#!/usr/bin/gosh` beginnen.
+
+Damit funktionieren auch `ssh host befehl`, `scp` und `rsync`, wenn gosh als Login-Shell gesetzt ist. Befehle lassen sich mit `;`, `&&` und `||` verketten und mit Pipes verbinden, z. B. `ssh host 'cd /srv && git log | head'`.
+
+### Startdateien
+
+Beim Start liest gosh Startdateien und führt sie wie ein Skript in der laufenden Shell aus (Variablen, die dort gesetzt werden, bleiben also erhalten):
+
+| Shell                         | Dateien (in dieser Reihenfolge)              | abschalten mit  |
+|-------------------------------|----------------------------------------------|-----------------|
+| Login-Shell                   | `/etc/gosh/profile`, `~/.gosh_profile`       | `--noprofile`   |
+| interaktive Shell             | `/etc/gosh/goshrc`, `~/.goshrc`              | `--norc`        |
+
+- Eine Login-Shell ist gosh mit `-l` oder wenn `argv[0]` mit `-` beginnt (so starten `login`, `sshd` und `su -` die Shell). Eine interaktive Login-Shell liest erst die Profil-, dann die `goshrc`-Dateien.
+- `gosh -c '…'` und Skripte lesen keine Startdateien, außer als Login-Shell (`gosh -l -c '…'`).
+- Fehlende Dateien werden übersprungen. Fehler werden mit Datei und Zeile gemeldet (`gosh: ~/.goshrc:4: foo: command not found`), die übrigen Zeilen laufen trotzdem.
+- Bash-Dateien wie `/etc/profile` oder `~/.bashrc` liest gosh bewusst nicht, weil es deren Syntax (`if`, Funktionen, …) nicht versteht.
+- Mit `source datei` (oder `. datei`) lässt sich eine Datei auch später einlesen, z. B. nach einer Änderung: `source ~/.goshrc`.
+
+Beispiel für `~/.goshrc`:
+
+```bash
+# Eigene Programme zuerst
+export PATH=$HOME/bin:$HOME/go/bin:$PATH
+export EDITOR=vim
+
+# Prompt-Farben (Anführungszeichen wegen des ;)
+export GOSH_COLORS='user=1;38;5;208:path=38;5;205'
+
+# Weitere Einstellungen nur, wenn die Datei existiert
+test -f ~/.goshrc.local && source ~/.goshrc.local
+```
+
+Beispiel für `~/.gosh_profile` (wird nur von Login-Shells gelesen, z. B. beim Anmelden an der Konsole oder per `ssh host` ohne Befehl):
+
+```bash
+export LANG=de_DE.UTF-8
+export PATH=$HOME/bin:$PATH
+```
+
+### Befehlslisten und Exit-Status
+
+Mehrere Befehle in einer Zeile werden wie in `sh` verknüpft:
+
+| Liste      | Bedeutung                                         |
+|------------|---------------------------------------------------|
+| `a ; b`    | erst `a`, dann `b`                                |
+| `a && b`   | `b` nur, wenn `a` erfolgreich war (Exit-Status 0) |
+| `a \|\| b` | `b` nur, wenn `a` fehlgeschlagen ist              |
+
+`&&` und `||` werden von links nach rechts ausgewertet, `a && b || c` führt also `c` aus, wenn `a` oder `b` fehlschlägt. Variablen werden erst beim Ausführen des jeweiligen Befehls expandiert, `cd /tmp && echo $PWD` gibt also schon das neue Verzeichnis aus.
+
+`$?` (bzw. `${?}`) enthält den Exit-Status des letzten Befehls, `exit` ohne Argument beendet gosh mit diesem Status:
+
+```
+$ false; echo $?
+1
+$ gibtsnicht || echo "Status $?"
+gosh: gibtsnicht: command not found
+Status 127
+```
+
+Schlägt ein Programm fehl, gibt gosh selbst keine Meldung mehr aus (das Programm meldet den Fehler selbst), nur bei Fehlern von gosh, z. B. wenn ein Befehl nicht gefunden wird.
+
+### Wildcards
+
+Wörter mit `*`, `?` oder `[...]` werden durch die passenden Dateinamen ersetzt, sortiert:
+
+| Muster    | passt auf                                           |
+|-----------|-----------------------------------------------------|
+| `*`       | beliebig viele Zeichen (auch keine)                 |
+| `?`       | genau ein Zeichen                                   |
+| `[abc]`   | eines der Zeichen `a`, `b`, `c`                     |
+| `[a-z]`   | ein Zeichen aus dem Bereich                         |
+| `[!abc]`  | ein Zeichen außer `a`, `b`, `c` (auch `[^abc]`)     |
+
+```
+$ ls *.go
+main.go  main_test.go
+$ cat logs/2026-*/error.log
+$ ls -d */            # nur Verzeichnisse
+```
+
+- Muster gelten pro Pfadteil, `*` passt nie auf `/`: `*/*.go` findet `.go`-Dateien eine Ebene tiefer.
+- 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 $DIR/*.go` funktioniert dagegen, weil das `*` direkt in der Zeile steht.
+- Bei einer Umleitung muss das Muster genau eine Datei treffen (`> *.log`), sonst meldet gosh `ambiguous redirect`.
+
+### Pipes und Umleitungen
+
+```
+$ ls | sort -r | head -3
+$ make > build.log 2>&1
+$ grep -c error < build.log
+```
+
+| Syntax          | Bedeutung                                                  |
+|-----------------|------------------------------------------------------------|
+| `a \| b`        | stdout von `a` wird stdin von `b`                          |
+| `< datei`       | stdin aus `datei` lesen                                    |
+| `> datei`       | stdout in `datei` schreiben (wird überschrieben)           |
+| `>> datei`      | stdout an `datei` anhängen                                 |
+| `2> datei`      | stderr in `datei` schreiben (`2>>` hängt an)               |
+| `2>&1`          | stderr dorthin, wohin stdout gerade geht                   |
+| `>&2`           | stdout dorthin, wohin stderr gerade geht                   |
+| `&> datei`      | stdout und stderr in `datei` (`&>>` hängt an)              |
+| `> 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.
+
+### Job-Control
+
+In einer interaktiven Shell läuft jede Befehlszeile (bzw. jede Pipeline) als eigener *Job* in einer eigenen Prozessgruppe:
+
+```
+$ sleep 100 &                 # im Hintergrund starten
+[1] 12345
+$ vim notizen.txt             # Ctrl+Z hält vim an
+^Z
+[2]+  Stopped                 vim notizen.txt
+$ jobs
+[1]-  Running                 sleep 100 &
+[2]+  Stopped                 vim notizen.txt
+$ fg                          # vim wieder im Vordergrund
+$ bg %2                       # oder: angehaltenen Job im Hintergrund weiterlaufen lassen
+```
+
+| Befehl / Taste | Bedeutung                                                                 |
+|----------------|---------------------------------------------------------------------------|
+| `befehl &`     | startet den Befehl im Hintergrund, gosh wartet nicht auf ihn (`$?` ist 0) |
+| Ctrl+Z         | hält den Vordergrund-Job an (`$?` wird 128+SIGTSTP, unter Linux 148)      |
+| Ctrl+C         | bricht nur den Vordergrund-Job ab, nicht die Shell                        |
+| `jobs`         | listet laufende und angehaltene Jobs                                      |
+| `fg [%n]`      | holt Job `n` in den Vordergrund (und setzt ihn fort, falls angehalten)    |
+| `bg [%n]`      | setzt einen angehaltenen Job im Hintergrund fort                          |
+| `wait [%n]`    | wartet auf Job `n` bzw. auf alle Hintergrund-Jobs                         |
+
+- Ohne Angabe gilt der *aktuelle* Job (in `jobs` mit `+` markiert, der zuletzt angehaltene oder in den Hintergrund geschickte), `%-` ist der vorherige (`-`). `%n` und `n` meinen Job Nummer `n`.
+- Beendete Hintergrund-Jobs meldet gosh vor dem nächsten Prompt (`[1]+  Done   sleep 100`, bei Fehlern `Exit N`).
+- Liest ein Hintergrund-Job vom Terminal, wird er angehalten (wie in bash), mit `fg` bekommt er die Eingabe.
+- Die Terminal-Einstellungen werden gesichert und wiederhergestellt: Nach dem Anhalten von `vim` oder `less` funktioniert der Prompt normal, nach `fg` bekommt das Programm seine Einstellungen zurück.
+- `exit` (oder Ctrl+D) mit angehaltenen Jobs warnt einmal (`there are stopped jobs`), ein zweites `exit` direkt danach beendet gosh.
+- `cd`, `set`, `export`, `exit`, `source`, `fg`, `bg` und `wait` lassen sich nicht mit `&` im Hintergrund starten.
+- In Skripten und mit `gosh -c` gibt es keine Job-Control (kein Ctrl+Z, kein `fg`/`bg`), `&` und `wait` funktionieren aber. Hintergrund-Jobs lesen dort von `/dev/null`.
+- Einen Job beenden lässt sich mit `kill` über die Prozess-ID (z. B. `kill 12345`); `kill %1` versteht gosh noch nicht.
+
+### Farben
+
+Der Prompt wird über die Umgebungsvariable `GOSH_COLORS` eingefärbt. Sie besteht aus durch `:` getrennten Einträgen `schlüssel=code`:
+
+| Schlüssel | Teil des Prompts               | Standard            |
+|-----------|--------------------------------|---------------------|
+| `user`    | `user@host`                    | `1;32` (fett grün)  |
+| `root`    | `user@host`, wenn man root ist | `1;31` (fett rot)   |
+| `path`    | aktuelles Verzeichnis          | `1;34` (fett blau)  |
+
+Die Werte sind [ANSI-SGR-Codes](https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_(Select_Graphic_Rendition)_parameters), mehrere werden mit `;` kombiniert:
+
+- `1` fett, `2` blass, `3` kursiv, `4` unterstrichen
+- `30`–`37` Vordergrund, `90`–`97` helle Vordergrundfarben, `40`–`47` Hintergrund
+- `38;5;N` eine der 256 Farben, `38;2;R;G;B` Truecolor (sofern das Terminal es kann)
+
+Nicht angegebene Schlüssel behalten ihre Standardfarbe, ein leerer Wert (`path=`) schaltet die Farbe für diesen Teil ab. Ungültige Werte werden ignoriert. Da nur Ziffern und `;` erlaubt sind, lassen sich über die Variable keine beliebigen Escape-Sequenzen ins Terminal schreiben. `NO_COLOR` schaltet alle Farben ab.
+
+Gesetzt wird die Variable z. B. in `~/.profile` oder direkt in gosh (wirkt ab dem nächsten Prompt):
+
+```bash
+export GOSH_COLORS='user=1;33:path=1;36'   # in ~/.profile
+set 'GOSH_COLORS=user=1;33:path=1;36'      # in gosh
+```
+
+Ein paar Kombinationen zum Ausprobieren:
+
+```bash
+# Solarized: gelb und cyan
+GOSH_COLORS='user=33:path=36'
+
+# Sonnenuntergang: orange und pink (256 Farben)
+GOSH_COLORS='user=1;38;5;208:path=38;5;205'
+
+# Matrix: hellgrün und blassgrün
+GOSH_COLORS='user=1;92:path=2;32'
+
+# Dracula: lila und pink (Truecolor)
+GOSH_COLORS='user=1;38;2;189;147;249:path=38;2;255;121;198'
+
+# Nord: frostblau und hellgrau (Truecolor)
+GOSH_COLORS='user=1;38;2;136;192;208:path=38;2;216;222;233'
+
+# Ozean: türkis und kursiv blau
+GOSH_COLORS='user=1;96:path=3;94'
+
+# Root-Warnung: weiß auf rotem Hintergrund
+GOSH_COLORS='root=1;97;41'
+
+# Dezent: nur das Verzeichnis unterstrichen
+GOSH_COLORS='user=:path=4'
+```
+
 ### Sicherheitshinweise
 
 - Die History liegt in `$XDG_STATE_HOME/gosh/history` (Standard: `~/.local/state/gosh/history`) und ist nur für den eigenen Benutzer lesbar (Verzeichnis `0700`, Datei `0600`). Mit `GOSH_HISTFILE` lässt sich ein anderer Pfad setzen, mit `GOSH_HISTFILE=` wird die History abgeschaltet.
@@ -45,6 +293,15 @@ _gosh is not meant for production use, it is just a proof of concept._
 go build ./
 ```
 
+Die Version lässt sich mit `gosh -version` (oder `--version`, `-V`) abfragen und steht auch in der Ausgabe von `help`:
+
+```
+$ gosh -version
+gosh 0.2.1 (branch: main, commit: 03e791c)
+```
+
+Version und Branch werden beim Bauen mit GoReleaser per `-ldflags` gesetzt. Bei einem einfachen `go build` steht dort `dev`, der Commit wird dann aus den von Go eingebetteten Git-Informationen gelesen (mit `-dirty`, falls es uncommittete Änderungen gab).
+
 ## Release
 
 Binaries sowie `.deb`- und `.rpm`-Pakete werden mit [GoReleaser](https://goreleaser.com) gebaut (Konfiguration: `.goreleaser.yaml`).

go.mod

@@ -7,4 +7,4 @@ require (
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 )
 
-require golang.org/x/sys v0.48.0 // indirect
+require golang.org/x/sys v0.48.0

jobs.go

@@ -0,0 +1,525 @@
+package main
+
+// Job control: in an interactive shell every pipeline runs in its own process
+// group, which gets the terminal while it runs in the foreground. Ctrl+Z stops
+// the foreground job, "&" starts a job in the background, and the builtins
+// jobs, fg, bg and wait manage the jobs. Without a terminal (scripts, gosh -c)
+// there is no job control, but "&" and wait still work.
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"os/signal"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"github.com/chzyer/readline"
+	"golang.org/x/sys/unix"
+)
+
+// proc is a stage of a job: a process, or a builtin or a stage that failed to
+// start (both without process).
+type proc struct {
+	cmd      *exec.Cmd  // nil if the stage is no process
+	done     chan error // the result of a stage without process
+	finished bool
+	stopped  bool
+	err      error
+}
+
+// job is a pipeline that was started by the shell.
+type job struct {
+	id    int    // number in the job table, 0 if not in the table
+	pgid  int    // process group, 0 without job control or processes
+	text  string // the command line
+	procs []*proc
+	tty   *readline.State // terminal modes of the job when it was stopped
+}
+
+var (
+	jobControl       bool            // job control is enabled
+	interactiveShell bool            // the shell reads commands from a user
+	ttyFd            int             // the terminal of the shell
+	shellPgid        int             // the process group of the shell
+	origPgid         int             // the foreground process group at start
+	shellTTY         *readline.State // terminal modes of the shell
+	jobTable         []*job          // background and stopped jobs
+	exitWarned       bool            // "there are stopped jobs" was shown
+)
+
+// initJobControl enables job control if stdin is a terminal: the shell moves
+// into its own process group and takes the terminal.
+func initJobControl() {
+	fd := int(os.Stdin.Fd())
+	if !readline.IsTerminal(fd) {
+		return
+	}
+	pgrp, err := unix.IoctlGetInt(fd, unix.TIOCGPGRP)
+	if err != nil {
+		return
+	}
+	pid := os.Getpid()
+	if syscall.Getpgrp() != pid {
+		if err := syscall.Setpgid(0, 0); err != nil {
+			return
+		}
+	}
+	origPgid, ttyFd, shellPgid = pgrp, fd, pid
+	if err := setForeground(pid); err != nil {
+		return
+	}
+	// Ctrl+Z must not stop the shell itself. (signal.Ignore would be
+	// inherited by the child processes.)
+	signal.Notify(make(chan os.Signal, 1), syscall.SIGTSTP)
+	jobControl = true
+}
+
+// releaseTerminal gives the terminal back to the process group that had it
+// when the shell started.
+func releaseTerminal() {
+	if jobControl && origPgid > 0 && origPgid != shellPgid {
+		setForeground(origPgid)
+	}
+}
+
+// setForeground makes pgid the foreground process group of the terminal.
+func setForeground(pgid int) error {
+	// The shell gets SIGTTOU if it does this while it is in the background
+	// (when it takes the terminal back from a job), unless the signal is
+	// ignored. It is only ignored for this call, since ignored signals are
+	// inherited by child processes.
+	signal.Ignore(syscall.SIGTTOU)
+	defer signal.Reset(syscall.SIGTTOU)
+	return unix.IoctlSetPointerInt(ttyFd, unix.TIOCSPGRP, pgid)
+}
+
+// ttyIndex returns the index of the file in fds that is the terminal of the
+// shell, or -1.
+func ttyIndex(fds [3]*os.File) int {
+	tty, err := os.Stdin.Stat()
+	if err != nil {
+		return -1
+	}
+	for i, f := range fds {
+		if info, err := f.Stat(); err == nil && os.SameFile(info, tty) {
+			return i
+		}
+	}
+	return -1
+}
+
+// finishedProc returns a proc without process that already has its result.
+func finishedProc(err error) *proc {
+	p := &proc{done: make(chan error, 1)}
+	p.done <- err
+	return p
+}
+
+// running reports whether a process of the job is running.
+func (j *job) running() bool {
+	for _, p := range j.procs {
+		if p.cmd != nil && !p.finished && !p.stopped {
+			return true
+		}
+	}
+	return false
+}
+
+// stopped reports whether the job is stopped: no process is running, but
+// one is stopped.
+func (j *job) stopped() bool {
+	if j.running() {
+		return false
+	}
+	for _, p := range j.procs {
+		if p.stopped {
+			return true
+		}
+	}
+	return false
+}
+
+// finished reports whether all stages of the job have finished.
+func (j *job) finished() bool {
+	for _, p := range j.procs {
+		if !p.finished {
+			return false
+		}
+	}
+	return true
+}
+
+// update records a status change of process pid.
+func (j *job) update(pid int, ws syscall.WaitStatus) {
+	for _, p := range j.procs {
+		if p.cmd == nil || p.cmd.Process.Pid != pid {
+			continue
+		}
+		switch {
+		case ws.Stopped():
+			p.stopped = true
+		case ws.Continued():
+			p.stopped = false
+		default:
+			p.finished, p.stopped = true, false
+			p.err = waitStatusError(ws)
+			p.cmd.Process.Release()
+		}
+	}
+}
+
+// waitStatusError converts the status of a finished process into an error:
+// nil for exit code 0, otherwise a statusError with the exit code, or 128+n
+// if the process was killed by signal n.
+func waitStatusError(ws syscall.WaitStatus) error {
+	switch {
+	case ws.Signaled():
+		return statusError(128 + int(ws.Signal()))
+	case ws.ExitStatus() != 0:
+		return statusError(ws.ExitStatus())
+	}
+	return nil
+}
+
+// wait waits until no process of the job is running any more (all finished
+// or, with job control, stopped). With nohang it only collects the status
+// changes that are already available and does not block.
+func (j *job) wait(nohang bool) {
+	flags := 0
+	if jobControl && j.pgid != 0 {
+		flags |= syscall.WUNTRACED | syscall.WCONTINUED
+	}
+	if nohang {
+		flags |= syscall.WNOHANG
+	}
+
+	for {
+		// With job control all processes of the job are in its process
+		// group, otherwise they are waited for one by one.
+		target := 0
+		if jobControl && j.pgid != 0 {
+			if !j.running() && !(nohang && j.stopped()) {
+				break
+			}
+			target = -j.pgid
+		} else {
+			if nohang {
+				// Check every process once
+				for _, p := range j.procs {
+					if p.cmd == nil || p.finished {
+						continue
+					}
+					var ws syscall.WaitStatus
+					if pid, err := syscall.Wait4(p.cmd.Process.Pid, &ws, flags, nil); err == nil && pid > 0 {
+						j.update(pid, ws)
+					}
+				}
+				break
+			}
+			for _, p := range j.procs {
+				if p.cmd != nil && !p.finished {
+					target = p.cmd.Process.Pid
+					break
+				}
+			}
+			if target == 0 {
+				break
+			}
+		}
+
+		var ws syscall.WaitStatus
+		pid, err := syscall.Wait4(target, &ws, flags, nil)
+		if errors.Is(err, syscall.EINTR) {
+			continue
+		}
+		if err != nil {
+			// Should not happen; do not wait forever
+			for _, p := range j.procs {
+				if p.cmd != nil && !p.finished {
+					p.finished, p.stopped = true, false
+				}
+			}
+			break
+		}
+		if pid == 0 {
+			break // nohang and nothing changed
+		}
+		j.update(pid, ws)
+	}
+
+	// Stages without process (builtins in pipelines)
+	for _, p := range j.procs {
+		if p.cmd != nil || p.finished {
+			continue
+		}
+		if nohang || j.stopped() {
+			select {
+			case p.err = <-p.done:
+				p.finished = true
+			default:
+			}
+		} else {
+			p.err = <-p.done
+			p.finished = true
+		}
+	}
+}
+
+// result returns the error of the last stage of a finished job (so $? is its
+// exit status, like in sh) and prints the errors of the other stages.
+func (j *job) result() error {
+	for _, p := range j.procs[:len(j.procs)-1] {
+		printError(p.err)
+	}
+	return j.procs[len(j.procs)-1].err
+}
+
+// waitForeground waits for a job in the foreground. If it is stopped, it is
+// added to the job table.
+func waitForeground(j *job) error {
+	j.wait(false)
+	if jobControl && j.pgid != 0 {
+		setForeground(shellPgid)
+		if j.stopped() {
+			j.tty, _ = readline.GetState(ttyFd)
+		}
+		if shellTTY != nil {
+			readline.Restore(ttyFd, shellTTY)
+		}
+	}
+
+	if j.stopped() {
+		addJob(j)
+		fmt.Fprintln(os.Stderr)
+		fmt.Fprintln(os.Stderr, j.describe("Stopped"))
+		return statusError(128 + int(syscall.SIGTSTP))
+	}
+	removeJob(j)
+	j.wait(false) // wait for the builtins, if any
+	return j.result()
+}
+
+// addJob adds j to the job table (if it is not there yet) and makes it the
+// current job.
+func addJob(j *job) {
+	removeJob(j)
+	if j.id == 0 {
+		for _, other := range jobTable {
+			j.id = max(j.id, other.id)
+		}
+		j.id++
+	}
+	jobTable = append(jobTable, j)
+}
+
+// removeJob removes j from the job table.
+func removeJob(j *job) {
+	for i, other := range jobTable {
+		if other == j {
+			jobTable = append(jobTable[:i], jobTable[i+1:]...)
+			return
+		}
+	}
+}
+
+// describe formats a job for jobs and the notifications, like bash:
+// "[1]+  Stopped                 sleep 30". The current job (the last one in
+// the table, i.e. the one stopped or put into the background most recently) is
+// marked with +, the previous one with -.
+func (j *job) describe(state string) string {
+	mark := ' '
+	if n := len(jobTable); n > 0 && jobTable[n-1] == j {
+		mark = '+'
+	} else if n > 1 && jobTable[n-2] == j {
+		mark = '-'
+	}
+	text := j.text
+	if state == "Running" {
+		text += " &"
+	}
+	return fmt.Sprintf("[%d]%c  %-24s%s", j.id, mark, state, sanitize(text))
+}
+
+// state returns the state of a job for jobs and the notifications.
+func (j *job) state() string {
+	switch {
+	case j.stopped():
+		return "Stopped"
+	case !j.finished():
+		return "Running"
+	}
+	if status := exitStatus(j.procs[len(j.procs)-1].err); status != 0 {
+		return "Exit " + strconv.Itoa(status)
+	}
+	return "Done"
+}
+
+// hasStoppedJobs reports whether a job in the table is stopped.
+func hasStoppedJobs() bool {
+	for _, j := range jobTable {
+		if j.stopped() {
+			return true
+		}
+	}
+	return false
+}
+
+// reapJobs collects the status changes of the background jobs, reports
+// finished and newly stopped jobs (if notify is set) and removes finished
+// jobs from the table.
+func reapJobs(notify bool) {
+	for _, j := range append([]*job(nil), jobTable...) {
+		wasStopped := j.stopped()
+		j.wait(true)
+		switch {
+		case j.finished():
+			if notify {
+				for _, p := range j.procs {
+					printError(p.err)
+				}
+				fmt.Fprintln(os.Stderr, j.describe(j.state()))
+			}
+			removeJob(j)
+		case j.stopped() && !wasStopped:
+			addJob(j) // the current job now
+			if notify {
+				fmt.Fprintln(os.Stderr, j.describe("Stopped"))
+			}
+		}
+	}
+}
+
+// findJob returns the job for a job spec: %N or N for job N, %+, %% or nothing
+// for the current job, %- for the previous one.
+func findJob(cmd string, args []string) (*job, error) {
+	spec := "%+"
+	if len(args) > 1 {
+		spec = args[1]
+	}
+	n := len(jobTable)
+	switch spec {
+	case "%+", "%%", "%":
+		if n > 0 {
+			return jobTable[n-1], nil
+		}
+		return nil, fmt.Errorf("%s: current: no such job", cmd)
+	case "%-":
+		if n > 1 {
+			return jobTable[n-2], nil
+		}
+		return nil, fmt.Errorf("%s: previous: no such job", cmd)
+	}
+	id, err := strconv.Atoi(strings.TrimPrefix(spec, "%"))
+	if err == nil {
+		for _, j := range jobTable {
+			if j.id == id {
+				return j, nil
+			}
+		}
+	}
+	return nil, fmt.Errorf("%s: %s: no such job", cmd, sanitize(spec))
+}
+
+// continueJob sends SIGCONT to a stopped job.
+func continueJob(j *job) {
+	for _, p := range j.procs {
+		p.stopped = false
+	}
+	if j.pgid != 0 {
+		syscall.Kill(-j.pgid, syscall.SIGCONT)
+	}
+}
+
+// builtinJobs lists the jobs.
+func builtinJobs(stdout io.Writer) error {
+	for _, j := range jobTable {
+		j.wait(true)
+	}
+	for _, j := range append([]*job(nil), jobTable...) {
+		fmt.Fprintln(stdout, j.describe(j.state()))
+		if j.finished() {
+			removeJob(j)
+		}
+	}
+	return nil
+}
+
+// builtinFg continues a job in the foreground and waits for it.
+func builtinFg(args []string, stdout io.Writer) error {
+	if !jobControl {
+		return errors.New("fg: no job control")
+	}
+	j, err := findJob("fg", args)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintln(stdout, sanitize(j.text))
+
+	if j.pgid != 0 {
+		shellTTY, _ = readline.GetState(ttyFd)
+		if j.stopped() && j.tty != nil {
+			readline.Restore(ttyFd, j.tty)
+		}
+		setForeground(j.pgid)
+	}
+	continueJob(j)
+	return waitForeground(j)
+}
+
+// builtinBg continues a stopped job in the background.
+func builtinBg(args []string, stdout io.Writer) error {
+	if !jobControl {
+		return errors.New("bg: no job control")
+	}
+	j, err := findJob("bg", args)
+	if err != nil {
+		return err
+	}
+	if !j.stopped() {
+		return fmt.Errorf("bg: job %d already in background", j.id)
+	}
+	continueJob(j)
+	addJob(j) // the current job now
+	fmt.Fprintln(stdout, j.describe("Running"))
+	return nil
+}
+
+// builtinWait waits for a job, or for all background jobs. Stopped jobs are
+// not waited for.
+func builtinWait(args []string) error {
+	jobs := append([]*job(nil), jobTable...)
+	if len(args) > 1 {
+		j, err := findJob("wait", args)
+		if err != nil {
+			return err
+		}
+		jobs = []*job{j}
+	}
+
+	var err error
+	for _, j := range jobs {
+		j.wait(false)
+		err = nil
+		if j.finished() {
+			removeJob(j)
+			err = j.result()
+		}
+	}
+	return err
+}
+
+// exitShell exits the shell, unless there are stopped jobs and the user was
+// not warned yet (like bash).
+func exitShell(code int) error {
+	if interactiveShell && hasStoppedJobs() && !exitWarned {
+		exitWarned = true
+		return errors.New("there are stopped jobs")
+	}
+	releaseTerminal()
+	os.Exit(code)
+	return nil
+}

jobs_linux_test.go

@@ -0,0 +1,182 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"testing"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// openPty opens a new pseudo terminal and returns the master and slave side.
+func openPty(t *testing.T) (*os.File, *os.File) {
+	t.Helper()
+	master, err := os.OpenFile("/dev/ptmx", os.O_RDWR, 0)
+	if err != nil {
+		t.Skipf("no pty available: %v", err)
+	}
+	if err := unix.IoctlSetPointerInt(int(master.Fd()), unix.TIOCSPTLCK, 0); err != nil {
+		t.Fatal(err)
+	}
+	n, err := unix.IoctlGetInt(int(master.Fd()), unix.TIOCGPTN)
+	if err != nil {
+		t.Fatal(err)
+	}
+	slave, err := os.OpenFile("/dev/pts/"+strconv.Itoa(n), os.O_RDWR|syscall.O_NOCTTY, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return master, slave
+}
+
+// ptyShell is the shell running on a pseudo terminal.
+type ptyShell struct {
+	t      *testing.T
+	master *os.File
+	mu     sync.Mutex
+	out    bytes.Buffer
+	cmd    *exec.Cmd
+}
+
+func startPtyShell(t *testing.T) *ptyShell {
+	bin := buildShell(t)
+	master, slave := openPty(t)
+	cmd := exec.Command(bin, "--norc")
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = slave, slave, slave
+	cmd.Env = append(os.Environ(), "NO_COLOR=1")
+	// New session with the pty as controlling terminal, like a terminal
+	// emulator does
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true, Setctty: true, Ctty: 0}
+	if err := cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+	slave.Close()
+
+	s := &ptyShell{t: t, master: master, cmd: cmd}
+	go func() {
+		buf := make([]byte, 4096)
+		for {
+			n, err := master.Read(buf)
+			s.mu.Lock()
+			s.out.Write(buf[:n])
+			s.mu.Unlock()
+			if err != nil {
+				return
+			}
+		}
+	}()
+	t.Cleanup(func() {
+		cmd.Process.Kill()
+		cmd.Wait()
+		master.Close()
+	})
+	s.expect("$ ")
+	return s
+}
+
+func (s *ptyShell) send(text string) {
+	s.master.WriteString(text)
+}
+
+// expect waits until want appears in the output after the position of the
+// last match and consumes the output up to it.
+func (s *ptyShell) expect(want string) {
+	s.t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		s.mu.Lock()
+		out := s.out.String()
+		if i := strings.Index(out, want); i >= 0 {
+			s.out.Next(i + len(want))
+			s.mu.Unlock()
+			return
+		}
+		s.mu.Unlock()
+		time.Sleep(20 * time.Millisecond)
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.t.Fatalf("timeout waiting for %q, output:\n%s", want, s.out.String())
+}
+
+func TestJobControl(t *testing.T) {
+	s := startPtyShell(t)
+
+	// Ctrl+Z stops the foreground job, the shell gets the terminal back
+	s.send("sleep 30\n")
+	time.Sleep(300 * time.Millisecond)
+	s.send("\x1a")
+	s.expect("[1]+  Stopped                 sleep 30")
+	s.send("jobs\n")
+	s.expect("[1]+  Stopped                 sleep 30")
+
+	// bg continues it in the background
+	s.send("bg\n")
+	s.expect("[1]+  Running                 sleep 30 &")
+
+	// fg brings it back, Ctrl+C reaches only the job
+	s.send("fg %1\n")
+	s.expect("sleep 30")
+	time.Sleep(300 * time.Millisecond)
+	s.send("\x03")
+	s.send("echo status=$?\n")
+	s.expect("status=130")
+
+	// A pipeline is stopped and continued as a whole
+	s.send("sleep 30 | cat\n")
+	time.Sleep(300 * time.Millisecond)
+	s.send("\x1a")
+	s.expect("Stopped                 sleep 30 | cat")
+	s.send("fg\n")
+	time.Sleep(300 * time.Millisecond)
+	s.send("\x03")
+	s.send("echo pipeline=$?\n")
+	s.expect("pipeline=130")
+
+	// A background job that reads from the terminal is stopped (SIGTTIN),
+	// in the foreground it gets the input
+	s.send("cat &\n")
+	s.expect("[1] ")
+	time.Sleep(300 * time.Millisecond)
+	s.send("echo next\n")
+	s.expect("[1]+  Stopped                 cat")
+	s.send("fg\n")
+	time.Sleep(300 * time.Millisecond)
+	s.send("hello cat\n")
+	s.expect("hello cat\r\nhello cat")
+	s.send("\x04")
+	s.send("echo cat=$?\n")
+	s.expect("cat=0")
+
+	// Finished background jobs are reported before the next prompt
+	s.send("sleep 0.2 &\n")
+	time.Sleep(500 * time.Millisecond)
+	s.send("echo tick\n")
+	s.expect("Done                    sleep 0.2")
+
+	// exit warns about stopped jobs once
+	s.send("sleep 30\n")
+	time.Sleep(300 * time.Millisecond)
+	s.send("\x1a")
+	s.expect("Stopped")
+	s.send("exit\n")
+	s.expect("there are stopped jobs")
+	s.send("exit 0\n")
+
+	done := make(chan error, 1)
+	go func() { done <- s.cmd.Wait() }()
+	select {
+	case err := <-done:
+		if err != nil {
+			t.Errorf("shell exited with %v", err)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("shell did not exit")
+	}
+}

main_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"os"
 	"os/exec"
@@ -225,7 +226,7 @@ func TestShell_EndToEnd(t *testing.T) {
 
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
-			cmd := exec.Command("go", "run", "main.go")
+			cmd := exec.Command("go", "run", ".")
 			cmd.Stdin = strings.NewReader(tc.input)
 			var stdout, stderr bytes.Buffer
 			cmd.Stdout = &stdout
@@ -258,7 +259,7 @@ func TestShell_EOF_ExitsGracefully(t *testing.T) {
 	// Simulate EOF by sending empty input
 	// Note: When using piped input, readline doesn't print prompts
 	// So we just verify the shell exits cleanly
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -277,7 +278,7 @@ func TestShell_EOF_ExitsGracefully(t *testing.T) {
 func TestShell_EOF_AfterCommand(t *testing.T) {
 	// Test that EOF after a command works
 	// Note: When using piped input, readline doesn't print prompts
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("echo test\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -301,7 +302,7 @@ func TestShell_SIGINT_HandlerSetup(t *testing.T) {
 	// This test verifies that the shell doesn't panic when receiving signals
 	// We can't easily test SIGINT handling from a test, but we can verify
 	// the shell runs without crashing
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("echo test\nquit\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -457,7 +458,7 @@ func TestShell_ExitWithStatusCode(t *testing.T) {
 	}
 	
 	// Build the binary once
-	build := exec.Command("go", "build", "-o", "gosh_test", "main.go")
+	build := exec.Command("go", "build", "-o", "gosh_test", ".")
 	if err := build.Run(); err != nil {
 		t.Fatalf("failed to build: %v", err)
 	}
@@ -493,7 +494,7 @@ func TestShell_ExitWithStatusCode(t *testing.T) {
 // =============================================================================
 
 func TestShell_EnvExpansion_Home(t *testing.T) {
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("echo $HOME\nexit\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -512,7 +513,7 @@ func TestShell_EnvExpansion_Home(t *testing.T) {
 }
 
 func TestShell_EnvExpansion_Path(t *testing.T) {
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("echo $PATH\nexit\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -531,7 +532,7 @@ func TestShell_EnvExpansion_Path(t *testing.T) {
 }
 
 func TestShell_EnvExpansion_Braces(t *testing.T) {
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("echo ${HOME}\nexit\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -550,7 +551,7 @@ func TestShell_EnvExpansion_Braces(t *testing.T) {
 }
 
 func TestShell_EnvExpansion_CdWithVar(t *testing.T) {
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("cd $HOME\npwd\nexit\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -569,7 +570,7 @@ func TestShell_EnvExpansion_CdWithVar(t *testing.T) {
 }
 
 func TestShell_TildeExpansion_Ls(t *testing.T) {
-	cmd := exec.Command("go", "run", "main.go")
+	cmd := exec.Command("go", "run", ".")
 	cmd.Stdin = strings.NewReader("ls ~\nexit\n")
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
@@ -648,6 +649,21 @@ func TestExecInput_ExportNoArgs(t *testing.T) {
 	}
 }
 
+func TestVersionInfo(t *testing.T) {
+	origVersion, origCommit, origBranch := version, commit, branch
+	defer func() { version, commit, branch = origVersion, origCommit, origBranch }()
+
+	version, commit, branch = "1.2.3", "abc1234", "main"
+	if got := versionInfo(); got != "1.2.3 (branch: main, commit: abc1234)" {
+		t.Errorf("versionInfo() = %q", got)
+	}
+
+	branch = ""
+	if got := versionInfo(); got != "1.2.3 (commit: abc1234)" {
+		t.Errorf("versionInfo() without branch = %q", got)
+	}
+}
+
 func TestExecInput_Help(t *testing.T) {
 	// Just verify help doesn't return an error
 	// We can't easily capture stdout in a unit test without a pipe
@@ -843,6 +859,15 @@ func TestShellCompleter_Do(t *testing.T) {
 		{"ls " + tmpDir + "/ma", []string{"in.go"}, 2},
 		{"ls xyz", nil, 3},
 		{"ls ~", []string{"/"}, 1},
+		// Commands are completed after |, ;, && and ||, files after redirections
+		{"ls | gi", []string{"tty "}, 2},
+		{"ls|gi", []string{"tty "}, 2},
+		{"true; gi", []string{"tty "}, 2},
+		{"true && gi", []string{"tty "}, 2},
+		{"false || gi", []string{"tty "}, 2},
+		{"ls > ma", []string{"in.go"}, 2},
+		{"ls 2>ma", []string{"in.go"}, 2},
+		{"cat <ma", []string{"in.go"}, 2},
 	}
 	for _, tt := range tests {
 		got, length := completeLine(tt.line)
@@ -864,6 +889,9 @@ func TestMain(m *testing.M) {
 		panic(err)
 	}
 	os.Setenv("GOSH_HISTFILE", filepath.Join(dir, "history"))
+	// Never read the system's startup files; tests that read the user's
+	// files set $HOME themselves
+	sysConfDir = filepath.Join(dir, "etc")
 	code := m.Run()
 	os.RemoveAll(dir)
 	os.Exit(code)
@@ -1004,6 +1032,7 @@ func TestSanitize(t *testing.T) {
 }
 
 func TestGetPrompt_EscapesControlCharacters(t *testing.T) {
+	t.Setenv("NO_COLOR", "1")
 	origDir, _ := os.Getwd()
 	defer os.Chdir(origDir)
 
@@ -1024,6 +1053,68 @@ func TestGetPrompt_EscapesControlCharacters(t *testing.T) {
 	}
 }
 
+func TestBuildPrompt_Color(t *testing.T) {
+	got := buildPrompt("flow", "host", "~/src", false, &defaultColors)
+	want := "\x1b[1;32mflow@host\x1b[0m:\x1b[1;34m~/src\x1b[0m $ "
+	if got != want {
+		t.Errorf("buildPrompt() = %q, want %q", got, want)
+	}
+
+	got = buildPrompt("root", "host", "/", true, &defaultColors)
+	if !strings.HasPrefix(got, "\x1b[1;31mroot@host") {
+		t.Errorf("expected red user for root, got %q", got)
+	}
+
+	got = buildPrompt("flow", "host", "~/src", false, nil)
+	if got != "flow@host:~/src $ " {
+		t.Errorf("buildPrompt() without color = %q", got)
+	}
+
+	colors := promptColors{user: "38;5;208", path: ""}
+	got = buildPrompt("flow", "host", "~/src", false, &colors)
+	if got != "\x1b[38;5;208mflow@host\x1b[0m:~/src $ " {
+		t.Errorf("buildPrompt() with custom colors = %q", got)
+	}
+}
+
+func TestParseColors(t *testing.T) {
+	tests := []struct {
+		spec string
+		want promptColors
+	}{
+		{"", defaultColors},
+		{"user=1;33", promptColors{user: "1;33", root: "1;31", path: "1;34"}},
+		{"user=33:root=41;97:path=38;5;208", promptColors{user: "33", root: "41;97", path: "38;5;208"}},
+		{"path=", promptColors{user: "1;32", root: "1;31", path: ""}},
+		{"path=0m\x1b[2J", defaultColors}, // escape sequences are rejected
+		{"path=red", defaultColors},       // only numeric codes
+		{"foo=1:user", defaultColors},     // unknown key, missing value
+		{"user=35::path=36", promptColors{user: "35", root: "1;31", path: "36"}},
+	}
+	for _, tc := range tests {
+		if got := parseColors(tc.spec); got != tc.want {
+			t.Errorf("parseColors(%q) = %+v, want %+v", tc.spec, got, tc.want)
+		}
+	}
+}
+
+func TestBuildPrompt_ColorEscapesControlCharacters(t *testing.T) {
+	got := buildPrompt("flow", "host", "evil\x1b[2J\x07", false, &defaultColors)
+	if strings.Contains(got, "\x1b[2J") || strings.Contains(got, "\x07") {
+		t.Errorf("prompt contains control characters from path: %q", got)
+	}
+	if !strings.Contains(got, `evil\x1b[2J\x07`) {
+		t.Errorf("expected escaped path in prompt, got %q", got)
+	}
+}
+
+func TestUseColor_NoColor(t *testing.T) {
+	t.Setenv("NO_COLOR", "1")
+	if useColor() {
+		t.Error("expected no color when NO_COLOR is set")
+	}
+}
+
 func TestFilePathCompleter_SkipsControlCharacters(t *testing.T) {
 	dir := t.TempDir()
 	for _, name := range []string{"good", "go\x1b[31mred"} {
@@ -1095,7 +1186,7 @@ func TestShell_History(t *testing.T) {
 	histFile := filepath.Join(t.TempDir(), "gosh", "history")
 	workDir := t.TempDir()
 
-	cmd := exec.Command(bin)
+	cmd := exec.Command(bin, "-i", "--norc")
 	cmd.Dir = workDir
 	cmd.Env = append(os.Environ(), "GOSH_HISTFILE="+histFile)
 	cmd.Stdin = strings.NewReader("echo first\n set SECRET=hunter2\nexit\n")
@@ -1127,7 +1218,7 @@ func TestShell_History(t *testing.T) {
 func TestShell_SIGINTKillsOnlyChild(t *testing.T) {
 	bin := buildShell(t)
 
-	cmd := exec.Command(bin)
+	cmd := exec.Command(bin, "-i", "--norc")
 	// Own process group, so that we can signal it like the terminal does
 	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
 	stdin, err := cmd.StdinPipe()
@@ -1158,3 +1249,688 @@ func TestShell_SIGINTKillsOnlyChild(t *testing.T) {
 		t.Errorf("child was not interrupted (took %v)", elapsed)
 	}
 }
+
+func TestExecInput_PassesStdin(t *testing.T) {
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	origStdin := os.Stdin
+	os.Stdin = r
+	defer func() {
+		os.Stdin = origStdin
+		r.Close()
+	}()
+
+	if _, err := w.WriteString("hello\n"); err != nil {
+		t.Fatal(err)
+	}
+	w.Close()
+
+	out := filepath.Join(t.TempDir(), "out")
+	t.Setenv("GOSH_TEST_OUT", out)
+	if err := execInput(`sh -c 'read x; printf %s "$x" > "$GOSH_TEST_OUT"'`); err != nil {
+		t.Fatal(err)
+	}
+	got, err := os.ReadFile(out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != "hello" {
+		t.Errorf("command read %q from stdin, want %q", got, "hello")
+	}
+}
+
+func TestExitStatus(t *testing.T) {
+	tests := []struct {
+		input string
+		want  int
+	}{
+		{"true", 0},
+		{"false", 1},
+		{`sh -c "exit 42"`, 42},
+		{`sh -c "kill -TERM \$\$"`, 128 + 15},
+		{"gosh-no-such-command", 127},
+		{"cd /gosh-no-such-dir", 127},
+	}
+	for _, tc := range tests {
+		if got := exitStatus(execInput(tc.input)); got != tc.want {
+			t.Errorf("exitStatus(execInput(%q)) = %d, want %d", tc.input, got, tc.want)
+		}
+	}
+	if got := exitStatus(errors.New("other")); got != 1 {
+		t.Errorf("exitStatus(other error) = %d, want 1", got)
+	}
+}
+
+func TestRunScript(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+
+	dir := t.TempDir()
+	script := "#!/usr/bin/gosh\n" +
+		"# comment\n" +
+		"\n" +
+		"cd " + dir + "\n" +
+		"  # indented comment\n" +
+		"touch first\n" +
+		"false\n" +
+		"touch second" // no trailing newline
+	if got := runScript(strings.NewReader(script), ""); got != 0 {
+		t.Errorf("runScript() = %d, want 0", got)
+	}
+	for _, name := range []string{"first", "second"} {
+		if _, err := os.Stat(filepath.Join(dir, name)); err != nil {
+			t.Errorf("expected %s to be created: %v", name, err)
+		}
+	}
+
+	// The status of the last command is returned
+	if got := runScript(strings.NewReader("true\nsh -c 'exit 3'\n"), ""); got != 3 {
+		t.Errorf("runScript() = %d, want 3", got)
+	}
+}
+
+func TestRun_Options(t *testing.T) {
+	tests := []struct {
+		args []string
+		want int
+	}{
+		{[]string{"-c", "true"}, 0},
+		{[]string{"-c", "false"}, 1},
+		{[]string{"-l", "--noprofile", "-c", "sh -c 'exit 5'"}, 5},
+		{[]string{"-c"}, 2},
+		{[]string{"-x"}, 2},
+		{[]string{"/gosh/no/such/script"}, 127},
+	}
+	for _, tc := range tests {
+		if got := run(tc.args); got != tc.want {
+			t.Errorf("run(%q) = %d, want %d", tc.args, got, tc.want)
+		}
+	}
+}
+
+func TestReadLine_DoesNotReadAhead(t *testing.T) {
+	r := strings.NewReader("first\nsecond\n")
+	line, err := readLine(r)
+	if line != "first" || err != nil {
+		t.Fatalf("readLine() = %q, %v", line, err)
+	}
+	if r.Len() != len("second\n") {
+		t.Errorf("readLine() consumed more than one line, %d bytes left", r.Len())
+	}
+}
+
+func TestSplitList(t *testing.T) {
+	tests := []struct {
+		input string
+		want  []listItem
+	}{
+		{"", nil},
+		{"   ", nil},
+		{"# only a comment", nil},
+		{"ls", []listItem{{"", "ls", false}}},
+		{"a; b", []listItem{{"", "a", false}, {";", " b", false}}},
+		{"a;", []listItem{{"", "a", false}}},
+		{"a && b || c", []listItem{{"", "a ", false}, {"&&", " b ", false}, {"||", " c", false}}},
+		{`echo "a;b" 'c&&d' e\;f`, []listItem{{"", `echo "a;b" 'c&&d' e\;f`, false}}},
+		{`echo "x\"; y"`, []listItem{{"", `echo "x\"; y"`, false}}},
+		{"echo ${X:-a;b}; c", []listItem{{"", "echo ${X:-a;b}", false}, {";", " c", false}}},
+		{"echo a # b; c", []listItem{{"", "echo a ", false}}},
+		{"echo a#b; c", []listItem{{"", "echo a#b", false}, {";", " c", false}}},
+		{"echo a|b", []listItem{{"", "echo a|b", false}}},
+		{"a & b", []listItem{{"", "a ", true}, {";", " b", false}}},
+		{"a &", []listItem{{"", "a ", true}}},
+		{"a&", []listItem{{"", "a", true}}},
+		{"a 2>&1 &", []listItem{{"", "a 2>&1 ", true}}},
+		{"a &> f &", []listItem{{"", "a &> f ", true}}},
+		{"a >&2 && b", []listItem{{"", "a >&2 ", false}, {"&&", " b", false}}},
+		{`echo "a & b" \&`, []listItem{{"", `echo "a & b" \&`, false}}},
+	}
+	for _, tc := range tests {
+		got, err := splitList(tc.input)
+		if err != nil {
+			t.Errorf("splitList(%q) returned error: %v", tc.input, err)
+			continue
+		}
+		if !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("splitList(%q) = %+v, want %+v", tc.input, got, tc.want)
+		}
+	}
+}
+
+func TestSplitList_SyntaxErrors(t *testing.T) {
+	for _, input := range []string{"; a", "a ;; b", "&& a", "a &&", "a ||", "a && ; b", "a || && b", "& a", "a & && b", "a & & b"} {
+		if _, err := splitList(input); err == nil || !strings.Contains(err.Error(), "syntax error") {
+			t.Errorf("splitList(%q) = %v, want syntax error", input, err)
+		}
+	}
+}
+
+func TestExecInput_Lists(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("D", dir)
+	tests := []struct {
+		input   string
+		created []string
+		missing []string
+		status  int
+	}{
+		{"touch $D/a; touch $D/b", []string{"a", "b"}, nil, 0},
+		{"false; touch $D/c", []string{"c"}, nil, 0},
+		{"true && touch $D/d", []string{"d"}, nil, 0},
+		{"false && touch $D/e", nil, []string{"e"}, 1},
+		{"false || touch $D/f", []string{"f"}, nil, 0},
+		{"true || touch $D/g", nil, []string{"g"}, 0},
+		{"false && touch $D/h || touch $D/i", []string{"i"}, []string{"h"}, 0},
+		{"true && false || touch $D/j", []string{"j"}, nil, 0},
+		{"gosh-no-such-command || touch $D/k", []string{"k"}, nil, 0},
+		{"true && sh -c 'exit 4'", nil, nil, 4},
+	}
+	for _, tc := range tests {
+		execInput(tc.input)
+		if lastStatus != tc.status {
+			t.Errorf("%q: $? = %d, want %d", tc.input, lastStatus, tc.status)
+		}
+		for _, name := range tc.created {
+			if _, err := os.Stat(filepath.Join(dir, name)); err != nil {
+				t.Errorf("%q: expected %s to be created", tc.input, name)
+			}
+		}
+		for _, name := range tc.missing {
+			if _, err := os.Stat(filepath.Join(dir, name)); err == nil {
+				t.Errorf("%q: %s must not be created", tc.input, name)
+			}
+		}
+	}
+}
+
+func TestExecInput_ExpandsPerCommand(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	dir := t.TempDir()
+	out := filepath.Join(dir, "out")
+	t.Setenv("GOSH_TEST_OUT", out)
+	os.Unsetenv("GOSH_TEST_LIST")
+	defer os.Unsetenv("GOSH_TEST_LIST")
+
+	// The variable is set by the first command and used by the second one
+	err := execInput(`set GOSH_TEST_LIST=hello && sh -c 'printf %s "$GOSH_TEST_LIST" > "$GOSH_TEST_OUT"'`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, _ := os.ReadFile(out); string(got) != "hello" {
+		t.Errorf("got %q, want %q", got, "hello")
+	}
+}
+
+func TestExpandVar_LastStatus(t *testing.T) {
+	execInput("sh -c 'exit 3'")
+	for _, input := range []string{"$?", "${?}"} {
+		words, err := splitWords("echo " + input)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if words[1] != "3" {
+			t.Errorf("%s = %q, want %q", input, words[1], "3")
+		}
+	}
+	execInput("true")
+	if words, _ := splitWords("echo $?"); words[1] != "0" {
+		t.Errorf("$? = %q after true, want 0", words[1])
+	}
+}
+
+func TestExecInput_CommandNotFound(t *testing.T) {
+	err := execInput("gosh-no-such-command")
+	if err == nil || err.Error() != "gosh-no-such-command: command not found" {
+		t.Errorf("got %v, want command not found", err)
+	}
+	if lastStatus != 127 {
+		t.Errorf("$? = %d, want 127", lastStatus)
+	}
+}
+
+func TestTokenize_Operators(t *testing.T) {
+	tests := []struct {
+		input string
+		want  []token
+	}{
+		{"a | b", []token{{word: "a"}, {op: "|"}, {word: "b"}}},
+		{"a|b", []token{{word: "a"}, {op: "|"}, {word: "b"}}},
+		{"a > f", []token{{word: "a"}, {op: ">", fd: 1}, {word: "f"}}},
+		{"a >>f", []token{{word: "a"}, {op: ">>", fd: 1}, {word: "f"}}},
+		{"a < f", []token{{word: "a"}, {op: "<", fd: 0}, {word: "f"}}},
+		{"a 2>f", []token{{word: "a"}, {op: ">", fd: 2}, {word: "f"}}},
+		{"a 2>>f", []token{{word: "a"}, {op: ">>", fd: 2}, {word: "f"}}},
+		{"a 2>&1", []token{{word: "a"}, {op: ">&", fd: 2, dup: 1}}},
+		{"a >&2", []token{{word: "a"}, {op: ">&", fd: 1, dup: 2}}},
+		{"a 0<&2", []token{{word: "a"}, {op: "<&", fd: 0, dup: 2}}},
+		{"a &>f", []token{{word: "a"}, {op: "&>", fd: 1}, {word: "f"}}},
+		{"a &>>f", []token{{word: "a"}, {op: "&>>", fd: 1}, {word: "f"}}},
+		// Only a word of unquoted digits is a file descriptor
+		{"a x2>f", []token{{word: "a"}, {word: "x2"}, {op: ">", fd: 1}, {word: "f"}}},
+		{`a "2">f`, []token{{word: "a"}, {word: "2"}, {op: ">", fd: 1}, {word: "f"}}},
+		{"a 2 >f", []token{{word: "a"}, {word: "2"}, {op: ">", fd: 1}, {word: "f"}}},
+		// Quoted and escaped operators are words
+		{`echo "a|b" 'c>d' e\<f`, []token{{word: "echo"}, {word: "a|b"}, {word: "c>d"}, {word: "e<f"}}},
+		// A lone & is a word
+		{"a & b", []token{{word: "a"}, {word: "&"}, {word: "b"}}},
+		{"cat ~|x", []token{{word: "cat"}, {word: getHomeDir()}, {op: "|"}, {word: "x"}}},
+	}
+	for _, tc := range tests {
+		got, err := tokenize(tc.input)
+		if err != nil {
+			t.Errorf("tokenize(%q) returned error: %v", tc.input, err)
+			continue
+		}
+		// Patterns are tested in TestTokenize_Patterns
+		for i := range got {
+			got[i].pattern, got[i].glob = "", false
+		}
+		if !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("tokenize(%q) = %+v, want %+v", tc.input, got, tc.want)
+		}
+	}
+}
+
+func TestExecInput_SyntaxErrors(t *testing.T) {
+	for _, input := range []string{"echo a |", "| echo a", "echo a | | b", "echo a >", "echo a > | b", "echo a >&", "echo a 2>&x", "; a"} {
+		err := execInput(input)
+		if err == nil || !strings.Contains(err.Error(), "syntax error") {
+			t.Errorf("execInput(%q) = %v, want syntax error", input, err)
+		}
+		if lastStatus != 2 {
+			t.Errorf("execInput(%q): $? = %d, want 2", input, lastStatus)
+		}
+	}
+}
+
+func TestExecInput_PipesAndRedirections(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	dir := t.TempDir()
+	os.Chdir(dir)
+
+	read := func(name string) string {
+		data, err := os.ReadFile(filepath.Join(dir, name))
+		if err != nil {
+			t.Errorf("reading %s: %v", name, err)
+		}
+		return string(data)
+	}
+
+	tests := []struct {
+		input  string
+		file   string
+		want   string
+		status int
+	}{
+		{`printf 'b\na\nc\n' | sort | head -n 2 > out`, "out", "a\nb\n", 0},
+		{"echo one > f1; echo two >> f1", "f1", "one\ntwo\n", 0},
+		{"echo one > f2; echo two > f2", "f2", "two\n", 0},
+		{"tr a-z A-Z < f1 > f3", "f3", "ONE\nTWO\n", 0},
+		{"sh -c 'echo out; echo err >&2' > f4 2>&1", "f4", "out\nerr\n", 0},
+		{"sh -c 'echo out; echo err >&2' &> f5", "f5", "out\nerr\n", 0},
+		{"sh -c 'echo err >&2' 2> f6", "f6", "err\n", 0},
+		// 2>&1 before >file sends stderr to the old stdout (the pipe)
+		{"sh -c 'echo out; echo err >&2' 2>&1 > /dev/null | cat > f7", "f7", "err\n", 0},
+		{"sh -c 'echo err >&2' 2>&1 | tr a-z A-Z > f8", "f8", "ERR\n", 0},
+		// Builtins write to redirections and pipes
+		{"pwd > f9", "f9", dir + "\n", 0},
+		{"pwd | cat > f10", "f10", dir + "\n", 0},
+		{"help | head -n 1 > f11", "f11", "gosh - Go Shell\n", 0},
+		// Errors of builtins go to the redirected stderr
+		{"cd /gosh/no/such/dir 2> f12", "f12", "gosh: chdir /gosh/no/such/dir: no such file or directory\n", 1},
+		// The status of a pipeline is the one of the last command
+		{"false | true > f13", "f13", "", 0},
+		{"true | false > f14", "f14", "", 1},
+		// A redirection without a command creates the file
+		{"> f15", "f15", "", 0},
+		// SIGPIPE ends the writer when the reader exits
+		{"yes | head -n 1 > f16", "f16", "y\n", 0},
+		// A command that is not found does not stop the pipeline
+		{"gosh-no-such-command | echo after > f17", "f17", "after\n", 0},
+		{"echo before | gosh-no-such-command 2> f18", "f18", "", 127},
+	}
+	for _, tc := range tests {
+		execInput(tc.input)
+		if lastStatus != tc.status {
+			t.Errorf("%q: $? = %d, want %d", tc.input, lastStatus, tc.status)
+		}
+		if got := read(tc.file); got != tc.want {
+			t.Errorf("%q: %s = %q, want %q", tc.input, tc.file, got, tc.want)
+		}
+	}
+}
+
+func TestExecInput_RedirectionErrors(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(t.TempDir())
+
+	tests := []struct {
+		input   string
+		wantErr string
+	}{
+		{"cat < gosh-no-such-file", "gosh-no-such-file: no such file or directory"},
+		{"echo a > gosh-no-such-dir/f", "gosh-no-such-dir/f: no such file or directory"},
+		{"echo a 3> f", "3: bad file descriptor"},
+		{"echo a 2>&5", "5: bad file descriptor"},
+		{"echo a | cd /", "cd: cannot be used in a pipeline"},
+		{"echo a | exit 3", "exit: cannot be used in a pipeline"},
+	}
+	for _, tc := range tests {
+		err := execInput(tc.input)
+		if err == nil || err.Error() != tc.wantErr {
+			t.Errorf("execInput(%q) = %v, want %q", tc.input, err, tc.wantErr)
+		}
+		if lastStatus != 1 {
+			t.Errorf("execInput(%q): $? = %d, want 1", tc.input, lastStatus)
+		}
+	}
+	// The command is not run if a redirection fails
+	if _, err := os.Stat("f"); err == nil {
+		t.Error("file f must not be created for a bad file descriptor")
+	}
+}
+
+func TestTokenize_Patterns(t *testing.T) {
+	t.Setenv("GOSH_GLOB", "*.go")
+	tests := []struct {
+		input   string
+		pattern string
+		glob    bool
+	}{
+		{"*.go", "*.go", true},
+		{"a?c", "a?c", true},
+		{"[ab].go", "[ab].go", true},
+		{"[!a].go", "[^a].go", true},
+		{"plain", "plain", false},
+		// Quoted, escaped and expanded characters are literal
+		{`"*.go"`, `\*.go`, false},
+		{`'*'.go`, `\*.go`, false},
+		{`\*.go`, `\*.go`, false},
+		{`"x"*`, `x*`, true},
+		{"$GOSH_GLOB", `\*.go`, false},
+		{`'['!a].go`, `\[!a].go`, 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].pattern != tc.pattern || tokens[0].glob != tc.glob {
+			t.Errorf("tokenize(%q): pattern %q, glob %v; want %q, %v",
+				tc.input, tokens[0].pattern, tokens[0].glob, tc.pattern, tc.glob)
+		}
+	}
+}
+
+func TestExpandGlob(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	dir := t.TempDir()
+	os.Chdir(dir)
+	for _, d := range []string{"sub/deep", "other"} {
+		os.MkdirAll(d, 0755)
+	}
+	for _, f := range []string{"a.go", "b.go", "c.txt", ".hidden.go", "with space.go", "[x].go", "sub/s1.go", "sub/deep/d.go", "other/o.go"} {
+		os.WriteFile(f, nil, 0644)
+	}
+
+	tests := []struct {
+		pattern string
+		want    []string
+	}{
+		{"*.go", []string{"[x].go", "a.go", "b.go", "with space.go"}},
+		{".*.go", []string{".hidden.go"}},
+		{"?.go", []string{"a.go", "b.go"}},
+		{"[ab].go", []string{"a.go", "b.go"}},
+		{"[^a].go", []string{"b.go"}},
+		{"*/*.go", []string{"other/o.go", "sub/s1.go"}},
+		{"*/", []string{"other/", "sub/"}},
+		{"sub/*/*.go", []string{"sub/deep/d.go"}},
+		{"./c*", []string{"./c.txt"}},
+		{dir + "/c*", []string{dir + "/c.txt"}},
+		{`\[x\].go`, []string{"[x].go"}},
+		{"*.xyz", nil},
+		{"[", nil},
+	}
+	for _, tc := range tests {
+		if got := expandGlob(tc.pattern); !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("expandGlob(%q) = %q, want %q", tc.pattern, got, tc.want)
+		}
+	}
+}
+
+func TestExecInput_Wildcards(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	dir := t.TempDir()
+	os.Chdir(dir)
+	for _, f := range []string{"a.go", "b.go", "c.txt"} {
+		os.WriteFile(f, []byte(f+"\n"), 0644)
+	}
+
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{"echo *.go > out", "a.go b.go\n"},
+		{"cat *.go > out", "a.go\nb.go\n"},
+		// No match: the word is passed on unchanged, like in sh
+		{"echo *.xyz > out", "*.xyz\n"},
+		{`echo "*.go" '?.go' \*.go > out`, "*.go ?.go *.go\n"},
+		// A redirection to a pattern with a single match uses that file
+		{"echo hi > *.txt; cat c.txt > out", "hi\n"},
+	}
+	for _, tc := range tests {
+		if err := execInput(tc.input); err != nil {
+			t.Errorf("execInput(%q) returned error: %v", tc.input, err)
+		}
+		if got, _ := os.ReadFile("out"); string(got) != tc.want {
+			t.Errorf("%q: got %q, want %q", tc.input, got, tc.want)
+		}
+	}
+
+	err := execInput("echo hi > *.go")
+	if err == nil || err.Error() != "*.go: ambiguous redirect" {
+		t.Errorf("expected ambiguous redirect error, got %v", err)
+	}
+}
+
+func TestStartupFiles(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	sys := sysConfDir
+
+	tests := []struct {
+		login, interactive bool
+		want               []string
+	}{
+		{false, false, nil},
+		{true, false, []string{sys + "/profile", home + "/.gosh_profile"}},
+		{false, true, []string{sys + "/goshrc", home + "/.goshrc"}},
+		{true, true, []string{sys + "/profile", home + "/.gosh_profile", sys + "/goshrc", home + "/.goshrc"}},
+	}
+	for _, tc := range tests {
+		if got := startupFiles(tc.login, tc.interactive); !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("startupFiles(%v, %v) = %q, want %q", tc.login, tc.interactive, got, tc.want)
+		}
+	}
+}
+
+func TestRun_LoginReadsProfile(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	os.Unsetenv("GOSH_TEST_PROFILE")
+	defer os.Unsetenv("GOSH_TEST_PROFILE")
+	os.WriteFile(filepath.Join(home, ".gosh_profile"), []byte("export GOSH_TEST_PROFILE=yes\n"), 0644)
+	// .goshrc is only read by interactive shells
+	os.WriteFile(filepath.Join(home, ".goshrc"), []byte("exit 99\n"), 0644)
+
+	check := `sh -c 'test "$GOSH_TEST_PROFILE" = yes'`
+	if got := run([]string{"-c", check}); got != 1 {
+		t.Errorf("non-login shell: status %d, want 1 (profile must not be read)", got)
+	}
+	if got := run([]string{"-l", "--noprofile", "-c", check}); got != 1 {
+		t.Errorf("--noprofile: status %d, want 1 (profile must not be read)", got)
+	}
+	if got := run([]string{"-l", "-c", check}); got != 0 {
+		t.Errorf("login shell: status %d, want 0 (profile must be read)", got)
+	}
+}
+
+func TestShell_InteractiveReadsRC(t *testing.T) {
+	bin := buildShell(t)
+	home := t.TempDir()
+	os.WriteFile(filepath.Join(home, ".goshrc"), []byte("export GOSH_TEST_RC=from-rc\n"), 0644)
+	os.WriteFile(filepath.Join(home, ".gosh_profile"), []byte("export GOSH_TEST_PROFILE=from-profile\n"), 0644)
+
+	tests := []struct {
+		args []string
+		want string
+	}{
+		{[]string{"-i"}, "from-rc -\n"},
+		{[]string{"-i", "--norc"}, "- -\n"},
+		{[]string{"-i", "-l"}, "from-rc from-profile\n"},
+		{[]string{"-i", "-l", "--norc", "--noprofile"}, "- -\n"},
+	}
+	for _, tc := range tests {
+		cmd := exec.Command(bin, tc.args...)
+		cmd.Env = append(os.Environ(), "HOME="+home)
+		cmd.Stdin = strings.NewReader("echo ${GOSH_TEST_RC:--} ${GOSH_TEST_PROFILE:--}\nexit\n")
+		out, err := cmd.Output()
+		if err != nil {
+			t.Fatalf("%v: %v", tc.args, err)
+		}
+		if !strings.HasSuffix(string(out), tc.want) {
+			t.Errorf("%v: output %q, want suffix %q", tc.args, out, tc.want)
+		}
+	}
+}
+
+func TestExecInput_Source(t *testing.T) {
+	dir := t.TempDir()
+	os.Unsetenv("GOSH_TEST_SOURCE")
+	defer os.Unsetenv("GOSH_TEST_SOURCE")
+
+	file := filepath.Join(dir, "vars")
+	os.WriteFile(file, []byte("# comment\nexport GOSH_TEST_SOURCE=hello\nsh -c 'exit 4'\n"), 0644)
+
+	for _, cmd := range []string{"source", "."} {
+		os.Unsetenv("GOSH_TEST_SOURCE")
+		execInput(cmd + " " + file)
+		if os.Getenv("GOSH_TEST_SOURCE") != "hello" {
+			t.Errorf("%s: variable was not set in the current shell", cmd)
+		}
+		if lastStatus != 4 {
+			t.Errorf("%s: $? = %d, want 4 (status of the last command)", cmd, lastStatus)
+		}
+	}
+
+	err := execInput("source " + filepath.Join(dir, "missing"))
+	if err == nil || !strings.Contains(err.Error(), "source: "+dir+"/missing: no such file or directory") {
+		t.Errorf("unexpected error for missing file: %v", err)
+	}
+	if lastStatus != 1 {
+		t.Errorf("$? = %d for missing file, want 1", lastStatus)
+	}
+
+	// A file that sources itself is stopped
+	loop := filepath.Join(dir, "loop")
+	os.WriteFile(loop, []byte("source "+loop+"\n"), 0644)
+	if err := execInput("source " + loop); err == nil {
+		t.Error("expected an error for a file that sources itself")
+	}
+}
+
+func TestGetHomeDir_UsesHOME(t *testing.T) {
+	t.Setenv("HOME", "/gosh/test/home")
+	if got := getHomeDir(); got != "/gosh/test/home" {
+		t.Errorf("getHomeDir() = %q, want $HOME", got)
+	}
+	if words, _ := splitWords("echo ~/x"); words[1] != "/gosh/test/home/x" {
+		t.Errorf("~/x = %q, want it based on $HOME", words[1])
+	}
+
+	// Without $HOME the user database is used
+	t.Setenv("HOME", "")
+	if got := getHomeDir(); got == "" {
+		t.Error("getHomeDir() is empty without $HOME")
+	}
+}
+
+func TestExecInput_Background(t *testing.T) {
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	dir := t.TempDir()
+	os.Chdir(dir)
+
+	// The shell does not wait for a background job, wait does
+	start := time.Now()
+	if err := execInput("sh -c 'sleep 0.3; echo done > out' &"); err != nil {
+		t.Fatal(err)
+	}
+	if lastStatus != 0 {
+		t.Errorf("$? = %d after starting a background job, want 0", lastStatus)
+	}
+	if time.Since(start) > 200*time.Millisecond {
+		t.Error("the shell waited for the background job")
+	}
+	if _, err := os.Stat("out"); err == nil {
+		t.Error("background job finished too early")
+	}
+	if err := execInput("wait"); err != nil {
+		t.Fatal(err)
+	}
+	if got, _ := os.ReadFile("out"); string(got) != "done\n" {
+		t.Errorf("out = %q after wait", got)
+	}
+	if len(jobTable) != 0 {
+		t.Errorf("job table not empty after wait: %d jobs", len(jobTable))
+	}
+
+	// wait %n returns the status of the job
+	execInput("sh -c 'exit 3' &")
+	execInput("wait %1")
+	if lastStatus != 3 {
+		t.Errorf("$? = %d after wait %%1, want 3", lastStatus)
+	}
+
+	// Without job control, background jobs read from /dev/null
+	execInput("cat > stdin.txt &")
+	execInput("wait")
+	if got, err := os.ReadFile("stdin.txt"); err != nil || len(got) != 0 {
+		t.Errorf("background job read %q, %v from stdin", got, err)
+	}
+
+	// jobs lists running jobs, also into a redirection
+	execInput("sleep 0.3 &")
+	execInput("jobs > jobs.txt")
+	if got, _ := os.ReadFile("jobs.txt"); !strings.Contains(string(got), "Running                 sleep 0.3 &") {
+		t.Errorf("jobs output = %q", got)
+	}
+	execInput("wait")
+
+	// Builtins that change the shell cannot run in the background
+	if err := execInput("cd / &"); err != nil {
+		t.Fatal(err)
+	}
+	execInput("wait %1")
+	if wd, _ := os.Getwd(); wd != dir {
+		t.Errorf("cd in the background changed the directory to %s", wd)
+	}
+
+	// fg and bg need job control
+	for _, cmd := range []string{"fg", "bg"} {
+		if err := execInput(cmd); err == nil || err.Error() != cmd+": no job control" {
+			t.Errorf("%s without job control: %v", cmd, err)
+		}
+	}
+	if err := execInput("wait %9"); err == nil || err.Error() != "wait: %9: no such job" {
+		t.Errorf("wait %%9: %v", err)
+	}
+}