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:not <not>, :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

See also

if is only as useful as the command used as the condition.

Fish ships a few:

• :doc:test can compare numbers, strings and check paths
• :doc:string can perform string operations including wildcard and regular expression matches
• :doc:path can check paths for permissions, existence or type
• :doc:contains can check if an element is in a list