fish-shell/sphinx_doc_src/cmds/begin.rst
2019-02-24 18:15:48 -08:00

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begin - start a new block of code
=================================
Synopsis
--------
begin; [COMMANDS...;] end
Description
-----------
``begin`` is used to create a new block of code.
A block allows the introduction of a new variable scope, redirection of the input or output of a set of commands as a group, or to specify precedence when using the conditional commands like ``and``.
The block is unconditionally executed. ``begin; ...; end`` is equivalent to ``if true; ...; end``.
``begin`` does not change the current exit status itself. After the block has completed, ``$status`` will be set to the status returned by the most recent command.
Example
-------
The following code sets a number of variables inside of a block scope. Since the variables are set inside the block and have local scope, they will be automatically deleted when the block ends.
::
begin
set -l PIRATE Yarrr
...
end
echo $PIRATE
# This will not output anything, since the PIRATE variable
# went out of scope at the end of the block
In the following code, all output is redirected to the file out.html.
::
begin
echo $xml_header
echo $html_header
if test -e $file
...
end
...
end > out.html