mirror of
https://github.com/fish-shell/fish-shell.git
synced 2024-11-25 18:03:37 +08:00
cf9b8fa3fa
This allows us to use :ref: references, which don't require hardcoding it as html [ci skip]
48 lines
809 B
ReStructuredText
48 lines
809 B
ReStructuredText
.. _cmd-isatty:
|
|
|
|
isatty - test if a file descriptor is a tty.
|
|
============================================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
isatty [FILE DESCRIPTOR]
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
``isatty`` tests if a file descriptor is a tty.
|
|
|
|
``FILE DESCRIPTOR`` may be either the number of a file descriptor, or one of the strings ``stdin``, ``stdout``, or ``stderr``.
|
|
|
|
If the specified file descriptor is a tty, the exit status of the command is zero. Otherwise, the exit status is non-zero. No messages are printed to standard error.
|
|
|
|
|
|
Examples
|
|
--------
|
|
|
|
From an interactive shell, the commands below exit with a return value of zero:
|
|
|
|
|
|
|
|
::
|
|
|
|
isatty
|
|
isatty stdout
|
|
isatty 2
|
|
echo | isatty 1
|
|
|
|
|
|
And these will exit non-zero:
|
|
|
|
|
|
|
|
::
|
|
|
|
echo | isatty
|
|
isatty 9
|
|
isatty stdout > file
|
|
isatty 2 2> file
|
|
|