mirror of
https://github.com/fish-shell/fish-shell.git
synced 2024-12-18 12:33:38 +08:00
50 lines
1.7 KiB
ReStructuredText
50 lines
1.7 KiB
ReStructuredText
case - conditionally execute a block of commands
|
|
================================================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
switch VALUE; [case [WILDCARD...]; [COMMANDS...]; ...] end
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
``switch`` executes one of several blocks of commands, depending on whether a specified value matches one of several values. ``case`` is used together with the ``switch`` statement in order to determine which block should be executed.
|
|
|
|
Each ``case`` command is given one or more parameters. The first ``case`` command with a parameter that matches the string specified in the switch command will be evaluated. ``case`` parameters may contain wildcards. These need to be escaped or quoted in order to avoid regular wildcard expansion using filenames.
|
|
|
|
Note that fish does not fall through on case statements. Only the first matching case is executed.
|
|
|
|
Note that command substitutions in a case statement will be evaluated even if its body is not taken. All substitutions, including command substitutions, must be performed before the value can be compared against the parameter.
|
|
|
|
|
|
Example
|
|
-------
|
|
|
|
Say \$animal contains the name of an animal. Then this code would classify it:
|
|
|
|
|
|
|
|
::
|
|
|
|
switch $animal
|
|
case cat
|
|
echo evil
|
|
case wolf dog human moose dolphin whale
|
|
echo mammal
|
|
case duck goose albatross
|
|
echo bird
|
|
case shark trout stingray
|
|
echo fish
|
|
# Note that the next case has a wildcard which is quoted
|
|
case '*'
|
|
echo I have no idea what a $animal is
|
|
end
|
|
|
|
|
|
If the above code was run with ``$animal`` set to ``whale``, the output
|
|
would be ``mammal``.
|
|
|
|
If ``$animal`` was set to "banana", it would print "I have no idea what a banana is".
|