TRAP(1) fish-shell TRAP(1)

# [NAME](#NAME)

trap - perform an action when the shell receives a signal

# [SYNOPSIS](#SYNOPSIS)

```
trap [OPTIONS] [[ARG] REASON ... ]
```

# [DESCRIPTION](#DESCRIPTION)

NOTE: This page documents the fish builtin **trap**. To see the documentation on any non-fish versions, use **command man trap**.

**trap** is a wrapper around the fish event delivery framework. It exists for backwards compatibility with POSIX shells. For other uses, it is recommended to define an event handler <#event>.

The following parameters are available:

[***ARG***](#ARG)

Command to be executed on signal delivery.

[***REASON***](#REASON)

Name of the event to trap. For example, a signal like **INT** or **SIGINT**, or the special symbol **EXIT**.

[**-l** or **--list-signals**](#l)

Prints a list of signal names.

[**-p** or **--print**](#p)

Prints all defined signal handlers.

[**-h** or **--help**](#h)

Displays help about using this command.

If *ARG* and *REASON* are both specified, *ARG* is the command to be executed when the event specified by *REASON* occurs (e.g., the signal is delivered).

If *ARG* is absent (and there is a single *REASON*) or **-**, each specified signal is reset to its original disposition (the value it had upon entrance to the shell). If *ARG* is the null string the signal specified by each *REASON* is ignored by the shell and by the commands it invokes.

If *ARG* is not present and **-p** has been supplied, then the trap commands associated with each *REASON* are displayed. If no arguments are supplied or if only **-p** is given, **trap** prints the list of commands associated with each signal.

Signal names are case insensitive and the **SIG** prefix is optional. Trapping a signal will prevent fish from exiting in response to that signal.

The exit status is 1 if any *REASON* is invalid; otherwise trap returns 0.

# [EXAMPLE](#EXAMPLE)

```
trap "status --print-stack-trace" SIGUSR1
# Prints a stack trace each time the SIGUSR1 signal is sent to the shell.
```

# [Copyright](#Copyright)

fish-shell developers

September 9, 2026 4.9

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Document: trap(1) from fish 4.9.3-r0 (Chainguard OS)
Source: https://github.com/fish-shell/fish-shell