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7a59540517
No need to define "cmd-foo" anchors; use :doc:`foo <cmds/foo>`
instead. If we want "cmd-foo" but it should be tested.
See also 38b24c2325 (docs: Use :doc: role when linking to commands,
2022-09-23).
62 lines
1.8 KiB
ReStructuredText
62 lines
1.8 KiB
ReStructuredText
if - conditionally execute a command
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====================================
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Synopsis
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--------
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.. synopsis::
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if CONDITION; COMMANDS_TRUE ...;
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[else if CONDITION2; COMMANDS_TRUE2 ...;]
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[else; COMMANDS_FALSE ...;]
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end
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Description
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-----------
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``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.
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You can use :doc:`and <and>` or :doc:`or <or>` in the condition. See the second example below.
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The exit status of the last foreground command to exit can always be accessed using the :ref:`$status <variables-status>` variable.
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The **-h** or **--help** option displays help about using this command.
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Example
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-------
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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``.
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::
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if test -f foo.txt
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echo foo.txt exists
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else if test -f bar.txt
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echo bar.txt exists
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else
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echo foo.txt and bar.txt do not exist
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end
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The following code will print "foo.txt exists and is readable" if foo.txt is a regular file and readable
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::
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if test -f foo.txt
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and test -r foo.txt
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echo "foo.txt exists and is readable"
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end
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See also
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--------
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``if`` is only as useful as the command used as the condition.
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Fish ships a few:
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- :doc:`test` can compare numbers, strings and check paths
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- :doc:`string` can perform string operations including wildcard and regular expression matches
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- :doc:`path` can check paths for permissions, existence or type
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- :doc:`contains` can check if an element is in a list
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