fish-shell/doc_src/cmds/count.rst

.. _cmd-count:

count - count the number of elements of a list
================================================

Synopsis
--------

| ``count`` string1 string2 ...
| *command* | ``count``
| ``count`` [...] < *FILE*

Description
-----------

``count`` prints the number of arguments that were passed to it, plus the number of newlines passed to it via stdin. This is usually used to find out how many elements an environment variable list contains, or how many lines there are in a text file.

``count`` does not accept any options, not even ``-h`` or ``--help``.

``count`` exits with a non-zero exit status if no arguments were passed to it, and with zero if at least one argument was passed.

Note that, like ``wc -l``, reading from stdin counts newlines, so ``echo -n foo | count`` will print 0.

Example
-------


::

    count $PATH
    # Returns the number of directories in the users PATH variable.
    
    count *.txt
    # Returns the number of files in the current working directory
    # ending with the suffix '.txt'.

    git ls-files --others --exclude-standard | count
    # Returns the number of untracked files in a git repository

    printf '%s\n' foo bar | count baz
    # Returns 3 (2 lines from stdin plus 1 argument)

    count < /etc/hosts
    # Counts the number of entries in the hosts file
docs: Add labels to all commands This allows us to use :ref: references, which don't require hardcoding it as html [ci skip] 2019-03-31 09:05:09 +00:00			`.. _cmd-count:`

docs: Call "arrays" "lists" We were flip-flopping between the two terms, so we now use one. We still mention "array" in the chapter, and it's still `read --array`, though. Fixes #5846. [ci skip] 2019-05-05 12:01:07 +00:00			`count - count the number of elements of a list`
Fix command section separator line lengths 2019-01-03 04:10:47 +00:00			`================================================`
Switch command docs from \section to reStructuredText 2018-12-17 01:39:33 +00:00
Migrate the 'synopsis' sections to .rst format 2018-12-18 01:58:24 +00:00			`Synopsis`
			`--------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
docs synopses: add space before ellipsis This matches the style in man(1) (except that we use the … ligature). A previous iteration did the reverse (never use a space before the ellipsis). That would be a smaller change. 2022-01-09 08:49:51 +00:00			\| ``count`` string1 string2 ...
Commit doc_src progress. This is continuing the work I've been doing to remove the :: formatting for the synopsis sections of our manual pages. 2021-12-17 21:58:38 +00:00			\| command \| ``count``
			\| ``count`` [...] < FILE
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
Convert \\subsection sections into rst format 2018-12-19 02:44:30 +00:00			`Description`
Fix command section separator line lengths 2019-01-03 04:10:47 +00:00			`-----------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
docs: Call "arrays" "lists" We were flip-flopping between the two terms, so we now use one. We still mention "array" in the chapter, and it's still `read --array`, though. Fixes #5846. [ci skip] 2019-05-05 12:01:07 +00:00			``count`` prints the number of arguments that were passed to it, plus the number of newlines passed to it via stdin. This is usually used to find out how many elements an environment variable list contains, or how many lines there are in a text file.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
Switch backticks to double backticks for rst compatibility 2018-12-19 20:02:45 +00:00			``count`` does not accept any options, not even ``-h`` or ``--help``.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
Switch backticks to double backticks for rst compatibility 2018-12-19 20:02:45 +00:00			``count`` exits with a non-zero exit status if no arguments were passed to it, and with zero if at least one argument was passed.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
[count] Allow counting lines from stdin As a simple replacement for `wc -l`. This counts both lines on stdin _and_ arguments. So if "file" has three lines, then `count a b c < file` will print 6. And since it counts newlines, like wc, `echo -n foo \| count` prints 0. 2018-01-03 23:42:12 +00:00			Note that, like ``wc -l``, reading from stdin counts newlines, so ``echo -n foo \| count`` will print 0.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
Convert \\subsection sections into rst format 2018-12-19 02:44:30 +00:00			`Example`
Fix command section separator line lengths 2019-01-03 04:10:47 +00:00			`-------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00

Switch \fish sections to rst format 2018-12-19 03:14:04 +00:00
			`::`

			`count $PATH`
			`# Returns the number of directories in the users PATH variable.`

			`count *.txt`
docs: Make more code lines shorter 2021-02-02 07:35:38 +00:00			`# Returns the number of files in the current working directory`
			`# ending with the suffix '.txt'.`
Switch \fish sections to rst format 2018-12-19 03:14:04 +00:00
[count] Allow counting lines from stdin As a simple replacement for `wc -l`. This counts both lines on stdin _and_ arguments. So if "file" has three lines, then `count a b c < file` will print 6. And since it counts newlines, like wc, `echo -n foo \| count` prints 0. 2018-01-03 23:42:12 +00:00			`git ls-files --others --exclude-standard \| count`
			`# Returns the number of untracked files in a git repository`

			`printf '%s\n' foo bar \| count baz`
			`# Returns 3 (2 lines from stdin plus 1 argument)`

			`count < /etc/hosts`
			`# Counts the number of entries in the hosts file`