mirror of
https://github.com/fish-shell/fish-shell
synced 2024-11-11 23:47:25 +00:00
45 lines
1.7 KiB
Text
45 lines
1.7 KiB
Text
\section trap trap - perform an action when the shell receives a signal
|
|
|
|
\subsection trap-synopsis Synopsis
|
|
\fish{synopsis}
|
|
trap [OPTIONS] [[ARG] SIGSPEC ... ]
|
|
\endfish
|
|
|
|
\subsection trap-description 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 <a
|
|
href='index.html#event'>event handler</a>.
|
|
|
|
The following parameters are available:
|
|
|
|
- `ARG` is the command to be executed on signal delivery.
|
|
- `SIGSPEC` is the name of the signal to trap.
|
|
- `-h` or `--help` displays help and exits.
|
|
- `-l` or `--list-signals` prints a list of signal names.
|
|
- `-p` or `--print` prints all defined signal handlers.
|
|
|
|
If `ARG` and `SIGSPEC` are both specified, `ARG` is the command to be
|
|
executed when the signal specified by `SIGSPEC` is delivered.
|
|
|
|
If `ARG` is absent (and there is a single SIGSPEC) 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 `SIGSPEC` 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 `SIGSPEC` 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 `SIGSPEC` is invalid; otherwise trap
|
|
returns 0.
|
|
|
|
\subsection trap-example Example
|
|
|
|
`trap "status --print-stack-trace" SIGUSR1` prints a stack trace
|
|
each time the `SIGUSR1` signal is sent to the shell.
|