@var
{metasyntactic-variable} ¶Use the @var
command to indicate metasyntactic variables. A
metasyntactic variable is something that stands for another
piece of text. For example, you should use a metasyntactic variable
in the documentation of a function to describe the arguments that are
passed to that function.
Do not use @var
for the names of normal variables in computer
programs. These are specific names, so @code
is correct for
them. For example, the Emacs Lisp variable texinfo-tex-command
is not a metasyntactic variable; it is properly formatted using @code
.
Do not use @var
for environment variables either; @env
is correct for them (see the next section).
The effect of @var
in the Info file is to change the case of
the argument to all uppercase. In the printed manual, the argument
is output in slanted type.
4
For example,
To delete file @var{filename}, type @samp{rm @var{filename}}.
produces
To delete file filename, type ‘rm filename’.
(Note that @var
may appear inside @code
,
@samp
, @file
, etc.)
Write a metasyntactic variable all in lowercase without spaces, and use hyphens to make it more readable. Thus, the Texinfo source for the illustration of how to begin a Texinfo manual looks like this:
\input texinfo @@settitle @var{name-of-manual}
This produces:
\input texinfo @settitle name-of-manual
In some documentation styles, metasyntactic variables are shown with angle brackets, for example:
..., type rm <filename>
However, that is not the style that Texinfo uses.
In TeX output, @var
currently uses a
slanted typewriter font in code contexts such as @code
or @example
. We plan to change this in the next release to
use a variable-width, slanted roman font in all contexts. To avoid
this change, set the ‘txicodevaristt’ flag using @set
;
specify ‘@clear txicodevaristt’ to make this change now
(see @set
and @value
). Note that this flag does nothing in
LaTeX output.