trap

trap(1)                              fish                              trap(1)



NAME
       trap - perform an action when the shell receives a signal

   Synopsis
       trap [OPTIONS] [[ARG] REASON ... ]

   Description
       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.

       The following parameters are available:

       · ARG is the command to be executed on signal delivery.

       · REASON is the name of the event to trap. For example, a signal like
         INT or SIGINT, or the special symbol EXIT.

       · -l or --list-signals prints a list of signal names.

       · -p or --print prints all defined signal handlers.

       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.

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

   Example
       trap 'status --print-stack-trace' SIGUSR1
         Prints a stack trace each time the SIGUSR1 signal is sent to the shell.

Version 3.0.2                   Tue Mar 26 2019                        trap(1)