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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/elgetpositionals.html | |
| download | execline-f316a2ed52195135a35e32d7096e876357c48c69.tar.xz | |
initial commit: rc for execline-2.0.0.0
Diffstat (limited to 'doc/elgetpositionals.html')
| -rw-r--r-- | doc/elgetpositionals.html | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/doc/elgetpositionals.html b/doc/elgetpositionals.html new file mode 100644 index 0000000..d193413 --- /dev/null +++ b/doc/elgetpositionals.html @@ -0,0 +1,94 @@ +<html> +<head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>execline: the elgetpositionals command</title> + <meta name="Description" content="execline: the elgetpositionals command" /> + <meta name="Keywords" content="execline command elgetpositionals arguments positional parameters" /> + <!-- <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>elgetpositionals</tt> program </h1> + +<p> +<tt>elgetpositionals</tt> substitutes the positional parameters of an execline script. +</p> + +<h2> Interface </h2> + +<pre> + elgetpositionals [ -P <em>sharp</em> ] <em>prog...</em> +</pre> + +<ul> + <li> <tt>elgetpositionals</tt> reads the number <em>n</em> of "positional +parameters" in the <tt>#</tt> environment variable. If that variable +is not set or does not contain a valid <em>n</em>, <tt>elgetpositionals</tt> +exits 100. </li> + <li> <tt>elgetpositionals</tt> performs some +<a href="el_substitute.html">substitutions</a> in parallel on +<em>prog...</em>: +<ul> + <li> key: <tt>#</tt>, value: <em>n</em> </li> + <li> key: <tt>0</tt>, value: the value of the <tt>0</tt> environment +variable </li> + <li> key: <tt>1</tt>, value: the value of the <tt>1</tt> environment +variable </li> + <li> ... and so on until <em>n</em> (or <em>sharp</em> if it is +greater than <em>n</em>). Those values are never transformed. </li> + <li> key: <tt>@</tt>, value: all values of the variables from <tt>1</tt> to +<tt><em>n</em></tt>. This value is <a href="el_transform.html#split">split</a> +into <em>n</em> words. </li> +</ul> + If a variable between <tt>0</tt> and <tt><em>n</em></tt> does not +exist, <tt>elgetpositionals</tt> exits 100. + </li> +</ul> + +<h2> Options </h2> + +<ul> + <li> <tt>-P</tt> <em>sharp</em> : substitute at least +<em>sharp</em>+1 positional parameters, from 0 to +max(<em>n</em>, <em>sharp</em>). If <em>n</em><<em>sharp</em>, +positional parameters between <em>n</em>+1 and <em>sharp</em> are +replaced with the empty string. Not having the <tt>-P</tt> switch is +equivalent to having <tt>-P 0</tt>. </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> A typical argument-taking execline script will +often begin that way: +<pre> + #!/command/execlineb + elgetopt <em>optstring</em> + elgetpositionals + <em>prog...</em> +</pre> +</li> + <li> If you are performing other substitutions that do not depend +on the positional parameters, think about replacing the +<tt>elgetpositionals</tt> call with a +<a href="multisubstitute.html">multisubstitute</a> call containing +the <tt>elgetpositionals</tt> directive. </li> + <li> If you are going to use the <a href="shift.html">shift</a> +command, it is best to use <a href="importas.html">importas</a> to +substitute the first positional parameters, then use <tt>shift</tt>, +then <tt>elgetpositionals</tt>. That way, <tt>$@</tt> will correctly +be replaced by the remaining arguments. More generally, you should +try to use <tt>elgetpositionals</tt> as late as possible. </li> + <li> Use <tt>execlineb</tt>'s <tt>-S</tt> switch instead of +<tt>elgetpositionals</tt> whenever you can. It is more efficient. </li> +</ul> + +</body> +</html> |