93 lines
2.3 KiB
HTML
93 lines
2.3 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
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<html>
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<head>
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<meta name="generator" content="HTML Tidy, see www.w3.org">
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<meta http-equiv="Content-Type" content=
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"text/html; charset=utf-8">
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<title>exec - Run commands and open, close, or copy
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descriptors</title>
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<LINK rel="stylesheet" type="text/css" href="../rzahg/ic.css">
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</HEAD>
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<body bgcolor="#FFFFFF">
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<!-- Java sync-link -->
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<SCRIPT LANGUAGE="Javascript" SRC="../rzahg/synch.js" TYPE="text/javascript"></SCRIPT>
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<h2>exec - Run commands and open, close, or copy descriptors</h2>
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<strong>Synopsis</strong>
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<p>
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<strong>exec [ -c ] [</strong> <em>command</em> <strong>[</strong> <em>argument ...</em>
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<strong>] ]</strong>
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</p>
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<p><strong>Description</strong></p>
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<p>The <strong>exec</strong> utility replaces <strong>
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qsh</strong> with <em>command</em> without creating a new process.
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The specified <em>arguments</em> are arguments to <em>
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command</em>. Any redirections affect the current environment.</p>
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<p>When a <em>command</em> is not specified, any redirections are
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processed in the current environment. Any file descriptors greater
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than 2 that are opened by a redirection are not inherited when
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<strong>qsh</strong> invokes another program.</p>
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<p><strong>Options</strong></p>
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<dl>
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<dt>
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<strong>-c</strong></dt>
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<dd>Run <em>command</em> with an empty set of environment variables.
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</dd>
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</dl>
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<p><strong>Operands</strong></p>
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<p>Each <em>argument</em> is assigned in order to the positional
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parameters of <em>command</em>.</p>
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<p><strong>Exit Status</strong></p>
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<p>Zero if no <em>command</em> is specified. Otherwise it does not
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return to <strong>qsh</strong>.</p>
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<p><strong>Related information</strong></p>
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<ul>
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<li><a href="command.htm">command - Run a simple command</a></li>
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<li><a href="dot.htm">dot (.) - Run commands in current
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environment</a></li>
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<li><a href="eval.htm">eval - Construct command by concatenating
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arguments</a></li>
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<li><a href="nohup.htm">nohup - Run utility without hangups</a></li>
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<li><a href="print.htm">print - Write output</a></li>
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<li><a href="read.htm">read - Read a line from standard
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input</a></li>
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</ul>
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<strong>Examples</strong>
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<ol>
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<li>Open a file for reading on descriptor 5:
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<pre>
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exec 5<$HOME/input
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</pre></li>
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<li>Close descriptor 5:
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<pre>
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exec 5<&-
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</pre></li>
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</ol>
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</body>
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</html>
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