fish/doc_src/begin.txt

\section begin begin - start a new block of code

\subsection begin-synopsis Synopsis
\fish{synopsis}
begin; [COMMANDS...;] end
\endfish

\subsection begin-description Description

`begin` is used to create a new block of code.

The block is unconditionally executed. `begin; ...; end` is equivalent to `if true; ...; end`.

`begin` is used to group a number of commands into a block. This 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`.

`begin` does not change the current exit status.


\subsection begin-example 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.

\fish
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
\endfish

In the following code, all output is redirected to the file out.html.

\fish
begin
    echo $xml_header
    echo $html_header
    if test -e $file
        ...
    end
    ...
end > out.html
\endfish