mirror of
https://github.com/fish-shell/fish-shell.git
synced 2024-11-23 02:27:28 +08:00
51 lines
1.4 KiB
ReStructuredText
51 lines
1.4 KiB
ReStructuredText
.. _cmd-for:
|
|
|
|
for - perform a set of commands multiple times
|
|
==============================================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
::
|
|
|
|
for VARNAME in [VALUES...]; COMMANDS...; end
|
|
|
|
Description
|
|
-----------
|
|
|
|
``for`` is a loop construct. It will perform the commands specified by ``COMMANDS`` multiple times. On each iteration, the local variable specified by ``VARNAME`` is assigned a new value from ``VALUES``. If ``VALUES`` is empty, ``COMMANDS`` will not be executed at all. The ``VARNAME`` is visible when the loop terminates and will contain the last value assigned to it. If ``VARNAME`` does not already exist it will be set in the local scope. For our purposes if the ``for`` block is inside a function there must be a local variable with the same name. If the ``for`` block is not nested inside a function then global and universal variables of the same name will be used if they exist.
|
|
|
|
Example
|
|
-------
|
|
|
|
|
|
|
|
::
|
|
|
|
for i in foo bar baz; echo $i; end
|
|
|
|
# would output:
|
|
foo
|
|
bar
|
|
baz
|
|
|
|
|
|
Notes
|
|
-----
|
|
|
|
The ``VARNAME`` was local to the for block in releases prior to 3.0.0. This means that if you did something like this:
|
|
|
|
|
|
|
|
::
|
|
|
|
for var in a b c
|
|
if break_from_loop
|
|
break
|
|
end
|
|
end
|
|
echo $var
|
|
|
|
|
|
The last value assigned to ``var`` when the loop terminated would not be available outside the loop. What ``echo $var`` would write depended on what it was set to before the loop was run. Likely nothing.
|