suspend

Additional Notes

suspend is a shell builtin (not a standalone command) that suspends the current shell's execution by sending it a SIGTSTP signal. This stops the shell process, returning control to its parent process. It is typically used within a subshell or a shell spawned by another program (like su, ssh, or sudo).

Typing suspend at a normal interactive shell will suspend it, returning to the shell that launched it. From there, the suspended shell can be resumed with fg (foreground) or bg (background). The command is mainly useful when you need to temporarily return to a parent shell without exiting the current one.

Syntax

suspend [-f]

Parameters

None.

Common Options

• -f: Force the suspension even if the shell is a login shell (which normally cannot be suspended).

Examples

suspend

Suspend the current shell and return to the parent shell.

# From within a subshell
(sh -c 'while true; do read cmd; eval $cmd; done')
# Press Ctrl-Z outside the subshell, or type 'suspend' inside

Use suspend from within a script or subshell to pause execution.

sudo -i
# ... inside root shell, then:
suspend -f

Force-suspend a root login shell (returns to the original user shell).

Practical Notes

• suspend is a shell builtin, not an external command. It is available in bash, zsh, dash, and other POSIX shells.
• Login shells cannot normally be suspended unless -f is used.
• To resume the suspended shell, type fg in the parent shell.
• Use jobs to see the suspended job's status.
• Not to be confused with system suspend (sleep/hibernate). Use systemctl suspend or pm-suspend for that.