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| author | Laurent Bercot <ska-skaware@skarnet.org> | 2021-11-26 07:00:11 +0000 |
|---|---|---|
| committer | Laurent Bercot <ska@appnovation.com> | 2021-11-26 07:00:11 +0000 |
| commit | 45ca80e0e1509c613f05cdb5fe8ec1157a4a7a48 (patch) | |
| tree | 08da8661a666889a0e84201af36f3d8834aeac10 /doc/case.html | |
| parent | 901efc65acfee5cad65a6ed84fc540c5ba6ebdf0 (diff) | |
| download | execline-45ca80e0e1509c613f05cdb5fe8ec1157a4a7a48.tar.xz | |
Add shell matching option to case
Signed-off-by: Laurent Bercot <ska@appnovation.com>
Diffstat (limited to 'doc/case.html')
| -rw-r--r-- | doc/case.html | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/doc/case.html b/doc/case.html index a82eec8..8ae817b 100644 --- a/doc/case.html +++ b/doc/case.html @@ -31,7 +31,7 @@ matches. </p> <pre> - case [ -E | -e ] [ -i ] [ -n | -N ] <em>value</em> + case [ -S | -s ] [ -E | -e ] [ -i ] [ -n | -N ] <em>value</em> { [ regex { <em>prog...</em> } ] [ regex { <em>prog...</em> } ] @@ -57,6 +57,13 @@ is empty. </li> <h2> Options </h2> <ul> + <li> <tt>-s</tt> : Shell matching. The <em>regex</em> words will not be +interpreted as regular expressions, but as shell expressions to be interpreted +via <a href="https://pubs.opengroup.org/onlinepubs/9699919799/functions/fnmatch.html">fnmatch()</a>. +The other options also change meanings, see the <em>Shell matching</em> section below. </li> + <li> <tt>-S</tt> : Regular expression matching. This is the default. This +section, and all of the sections below except the <em>Shell matching</em> one, +assumes that it is the case. </li> <li> <tt>-e</tt> : Interpret the <em>regex</em> words as <a href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03">basic regular expressions</a>. </li> @@ -116,6 +123,41 @@ to the output of the <tt>/usr/bin/env</tt> command: 2=baz </pre> +<h2> Shell matching </h2> + +<p> + If the <tt>-s</tt> option has been given to <tt>case</tt>, then the <em>regex</em> +words are not interpreted as regular expressions, but as shell patterns, as is +performed by the shell's +<a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_04_05">case</a> +conditional construct. This has the following consequences: +</p> + +<ul> + <li> Subexpression matching is always disabled. </li> + <li> <em>prog...</em> is always executed with an unmodified environment. </li> + <li> The options to the <tt>case</tt> command change meanings: instead of +controlling how the <em>regex</em> regular expressions are interpreted by the +<a href="https://pubs.opengroup.org/onlinepubs/9699919799/functions/regcomp.html">regcomp()</a> +primitive, they now control how <em>value</em> is matched against the <em>regex</em> patterns +(which are not regular expressions!) via the +<a href="https://pubs.opengroup.org/onlinepubs/9699919799/functions/fnmatch.html">fnmatch()</a> +primitive. Namely: + <ul> + <li> <tt>-e</tt> : Treat a backslash as an ordinary character; do not allow +character escaping in patterns. (This sets the <tt>FNM_NOESCAPE</tt> flag.) </li> + <li> <tt>-E</tt> : Allow backslash escaping in patterns. This is the default. +(This clears the <tt>FNM_NOESCAPE</tt> flag.) </li> + <li> <tt>-i</tt> : Treat a period (<tt>.</tt>) as a special character for +matching (set <tt>FNM_PERIOD</tt>). By default, the period is not a special character +(<tt>FNM_PERIOD</tt> is cleared). </li> + <li> <tt>-N</tt> : Treat patterns as pathnames: make slashes character special. +(This sets the <tt>FNM_PATHNAME</tt> flag.) </li> + <li> <tt>-n</tt> : Do not treat patterns as pathnames (clear the +<tt>FNM_PATHNAME</tt> flag). This is the default. </li> + </ul> </li> +</ul> + <h2> Notes </h2> <ul> |