Bash 5 reference · Shell Builtins and Syntax

trap (Bash builtin)

Run commands when the script exits or receives a signal; the standard way to clean up temporary files and child processes.

Bash 5

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Syntax

trap 'COMMANDS' EXIT | ERR | INT | TERM

Parameter	Description
`EXIT`	When the shell exits, for any reason.
`ERR`	When a command fails (with set -e).
`INT TERM`	Signals: Ctrl+C, termination.

Clean up on exit

bash -c 'tmp=$(mktemp); trap "rm -f $tmp; echo cleaned up" EXIT; echo working; exit 3'; echo "status $?"

Output

working
cleaned up
status 3

Run this on your computer — see “Get Started” for setup.

Report errors

bash -c 'trap "echo failed at line \$LINENO" ERR; set -e; true; false'; echo "status $?"

Output

failed at line 1
status 1

Run this on your computer — see “Get Started” for setup.

set -euo pipefail · Turn on strict mode: exit on errors (-e), fail on unset variables (-u), and fail pipelines when any part fails.
Bash Error Handling: set -euo pipefail and trap · tutorial