exit

What it does

How to write it

exit [N]
return [N]

Main parts

0

Success.

1

General error.

2

Wrong use (often from builtins).

126

Found, but cannot run.

127

Command not found.

128+N

Killed by signal N (130 = Ctrl+C, 137 = kill -9).

Most used

Nothing matches this filter.

$ run as a normal user# run as root (or with sudo)

1. 1End a script with success

   $tail -1 backup.sh
   exit 0

   The caller sees 0.

2. 2Exit with an error

   $[ -d /backup ] || { echo "no backup folder" >&2; exit 1; }

   Message to stderr, code 1.

3. 3See the status of the last command

   $ls /nothing; echo $?
   ls: cannot access '/nothing': No such file or directory
   2

   ls uses 2 for this error.

4. 4Command not found

   $nosuchcommand; echo $?
   127

   127 = not found.

5. 5Killed by Ctrl+C

   $sleep 100
   ^C
   $echo $?
   130

   128 + 2 (SIGINT).

6. 6Return from a function

   $isroot() { [ "$(id -u)" -eq 0 ] && return 0 || return 1; }; isroot && echo root || echo "not root"

   return = exit for functions.

7. 7Use the status in if

   $if grep -q lisa /etc/passwd; then echo found; fi

   if checks the exit status.

8. 8Pass on the status of the last command

   $cp a b; exit

   exit without N uses the status of cp.

9. 9Leave a root shell

   #exit

   Back to your own user.

10. 10Exit codes in systemd

    $systemctl status myapp | grep -i 'code='

    status=203/EXEC = the program could not be run.

Nothing matches this filter.

Exit codes