mirror of
https://github.com/fish-shell/fish-shell
synced 2024-09-20 22:42:04 +00:00
38b24c2325
This makes it so we link to the very top of the document instead of a special anchor we manually include. So clicking e.g. :doc:`string <cmds/string>` will link you to cmds/string.html instead of cmds/string.html#cmd-string. I would love to have a way to say "this document from the root of the document path", but that doesn't appear to work, I tried `/cmds/string`. So we'll just have to use cmds/string in normal documents and plain `string` from other commands.
54 lines
1.4 KiB
ReStructuredText
54 lines
1.4 KiB
ReStructuredText
.. _cmd-if:
|
|
|
|
if - conditionally execute a command
|
|
====================================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
.. synopsis::
|
|
|
|
if CONDITION; COMMANDS_TRUE ...;
|
|
[else if CONDITION2; COMMANDS_TRUE2 ...;]
|
|
[else; COMMANDS_FALSE ...;]
|
|
end
|
|
|
|
Description
|
|
-----------
|
|
|
|
``if`` will execute the command ``CONDITION``. If the condition's exit status is 0, the commands ``COMMANDS_TRUE`` will execute. If the exit status is not 0 and :doc:`else <else>` is given, ``COMMANDS_FALSE`` will be executed.
|
|
|
|
You can use :doc:`and <and>` or :doc:`or <or>` in the condition. See the second example below.
|
|
|
|
The exit status of the last foreground command to exit can always be accessed using the :ref:`$status <variables-status>` variable.
|
|
|
|
The **-h** or **--help** option displays help about using this command.
|
|
|
|
Example
|
|
-------
|
|
|
|
The following code will print ``foo.txt exists`` if the file foo.txt exists and is a regular file, otherwise it will print ``bar.txt exists`` if the file bar.txt exists and is a regular file, otherwise it will print ``foo.txt and bar.txt do not exist``.
|
|
|
|
|
|
|
|
::
|
|
|
|
if test -f foo.txt
|
|
echo foo.txt exists
|
|
else if test -f bar.txt
|
|
echo bar.txt exists
|
|
else
|
|
echo foo.txt and bar.txt do not exist
|
|
end
|
|
|
|
|
|
The following code will print "foo.txt exists and is readable" if foo.txt is a regular file and readable
|
|
|
|
|
|
::
|
|
|
|
if test -f foo.txt
|
|
and test -r foo.txt
|
|
echo "foo.txt exists and is readable"
|
|
end
|
|
|