/usr/share/doc/libnewlib-doc/libc.html/system.html is in libnewlib-doc 2.4.0.20160527-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Created by GNU Texinfo 6.3, http://www.gnu.org/software/texinfo/ -->
<head>
<title>The Red Hat newlib C Library: system</title>
<meta name="description" content="The Red Hat newlib C Library: system">
<meta name="keywords" content="The Red Hat newlib C Library: system">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Document-Index.html#Document-Index" rel="index" title="Document Index">
<link href="Document-Index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Stdlib.html#Stdlib" rel="up" title="Stdlib">
<link href="utoa.html#utoa" rel="next" title="utoa">
<link href="wcstoull.html#wcstoull" rel="prev" title="wcstoull">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en">
<a name="system"></a>
<div class="header">
<p>
Next: <a href="utoa.html#utoa" accesskey="n" rel="next">utoa</a>, Previous: <a href="wcstoull.html#wcstoull" accesskey="p" rel="prev">wcstoull</a>, Up: <a href="Stdlib.html#Stdlib" accesskey="u" rel="up">Stdlib</a> [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="system_002d_002d_002dexecute-command-string"></a>
<h3 class="section">2.48 <code>system</code>—execute command string</h3>
<a name="index-system"></a>
<a name="index-_005fsystem_005fr"></a>
<p><strong>Synopsis</strong>
</p><div class="example">
<pre class="example">#include <stdlib.h>
int system(char *<var>s</var>);
int _system_r(void *<var>reent</var>, char *<var>s</var>);
</pre></div>
<p><strong>Description</strong><br>
</p>
<p>Use <code>system</code> to pass a command string <code>*<var>s</var></code> to <code>/bin/sh</code> on
your system, and wait for it to finish executing.
</p>
<p>Use “<code>system(NULL)</code>” to test whether your system has <code>/bin/sh</code>
available.
</p>
<p>The alternate function <code>_system_r</code> is a reentrant version. The
extra argument <var>reent</var> is a pointer to a reentrancy structure.
</p>
<br>
<p><strong>Returns</strong><br>
<code>system(NULL)</code> returns a non-zero value if <code>/bin/sh</code> is available, and
<code>0</code> if it is not.
</p>
<p>With a command argument, the result of <code>system</code> is the exit status
returned by <code>/bin/sh</code>.
</p>
<br>
<p><strong>Portability</strong><br>
ANSI C requires <code>system</code>, but leaves the nature and effects of a
command processor undefined. ANSI C does, however, specify that
<code>system(NULL)</code> return zero or nonzero to report on the existence of
a command processor.
</p>
<p>POSIX.2 requires <code>system</code>, and requires that it invoke a <code>sh</code>.
Where <code>sh</code> is found is left unspecified.
</p>
<p>Supporting OS subroutines required: <code>_exit</code>, <code>_execve</code>, <code>_fork_r</code>,
<code>_wait_r</code>.
</p>
<br>
</body>
</html>
|