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| author | Laurent Bercot <ska-skaware@skarnet.org> | 2014-09-18 20:03:23 +0000 |
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| committer | Laurent Bercot <ska-skaware@skarnet.org> | 2014-09-18 20:03:23 +0000 |
| commit | f316a2ed52195135a35e32d7096e876357c48c69 (patch) | |
| tree | 5f4486b9a5a213a69e66ef574d6bc643a207981c /doc/loopwhilex.html | |
| download | execline-f316a2ed52195135a35e32d7096e876357c48c69.tar.xz | |
initial commit: rc for execline-2.0.0.0
Diffstat (limited to 'doc/loopwhilex.html')
| -rw-r--r-- | doc/loopwhilex.html | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/doc/loopwhilex.html b/doc/loopwhilex.html new file mode 100644 index 0000000..9def60f --- /dev/null +++ b/doc/loopwhilex.html @@ -0,0 +1,60 @@ +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>execline: the loopwhilex command</title> + <meta name="Description" content="execline: the loopwhilex command" /> + <meta name="Keywords" content="execline command loopwhilex" /> + <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">execline</a><br /> +<a href="http://skarnet.org/software/">Software</a><br /> +<a href="http://skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>loopwhilex</tt> program </h1> + +<p> +<tt>loopwhilex</tt> performs a conditional loop. +</p> + +<h2> Interface </h2> + +<pre> + loopwhilex [ -n ] [ -x <em>exitcodes</em> ] <em>prog...</em> +</pre> + +<ul> + <li> <tt>loopwhilex</tt> runs <em>prog...</em> as a child process and +waits for it to complete. </li> + <li> As long as <em>prog</em> exits zero, <tt>loopwhile</tt> runs it again. </li> + <li> <tt>loopwhilex</tt> then exits 0. If <em>prog</em> was killed by a signal, +<tt>loopwhilex</tt> exits that signal's number instead. </li> +</ul> + +<h2> Options </h2> + +<ul> + <li> <tt>-x</tt> <em>exitcodes</em> : <em>exitcodes</em> must be a comma-separated +list of valid exit codes. If this option is given, <tt>loopwhilex</tt> will exit if <em>prog...</em>'s +exit code is listed in <em>breakcodes</em>. </li> + <li> <tt>-n</tt> : negate the test: run <em>prog...</em> as long as it exits non-zero +(or exits a code that is <em>not</em> listed in <em>breakcodes</em>). </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> <tt>loopwhilex <em>prog</em>...</tt> is equivalent to <tt>loopwhilex -n -x 0 <em>prog...</em></tt>. </li> + <li> Be careful: execline <strong>maintains no state</strong>, in particular it +uses <strong>no real variables</strong>, and environment will +be of no use here since every instance of <em>prog...</em> runs as a separate +child process. To avoid being stuck in an infinite loop, <em>prog...</em> +should modify some external state - for instance, the filesystem. </li> +</ul> + +</body> +</html> |