getsubopt.html
来自「unix 下的C开发手册,还用详细的例程。」· HTML 代码 · 共 89 行
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"><html><head><!-- Copyright 1997 The Open Group, All Rights Reserved --><title>getsubopt</title></head><body bgcolor=white><center><font size=2>The Single UNIX ® Specification, Version 2<br>Copyright © 1997 The Open Group</font></center><hr size=2 noshade><h4><a name = "tag_000_005_749"> </a>NAME</h4><blockquote>getsubopt - parse suboption arguments from a string</blockquote><h4><a name = "tag_000_005_750"> </a>SYNOPSIS</h4><blockquote><pre><code>#include <<a href="stdlib.h.html">stdlib.h</a>>int getsubopt(char **<i>optionp</i>, char * const *<i>tokens</i>, char **<i>valuep</i>);</code></pre></blockquote><h4><a name = "tag_000_005_751"> </a>DESCRIPTION</h4><blockquote>The<i>getsubopt()</i>function parses suboption arguments in a flag argument that was initiallyparsed by<i><a href="getopt.html">getopt()</a></i>.These suboption arguments must be separated by commas and may consist ofeither a single token, or a token-value pair separated by an equal sign.Because commas delimit suboption arguments in the option string, they are notallowed to be part of the suboption arguments or the value of a suboptionargument. Similarly, because the equal sign separates a token from its value,a token must not contain an equal sign.<p>The<i>getsubopt()</i>function takes the address of a pointer to the option argument string, avector of possible tokens, and the address of a value string pointer. If theoption argument string at *<i>optionp</i> contains only one suboption argument,<i>getsubopt()</i>updates *<i>optionp</i> to point to the null at the end of the string.Otherwise, it isolates the suboption argument by replacing the comma separatorwith a null, and updates *<i>optionp</i> to point to the start of the nextsuboption argument. If the suboption argument has an associated value,<i>getsubopt()</i>updates *<i>valuep</i> to point to the value's first character. Otherwise itsets *<i>valuep</i> to a null pointer.<p>The token vector is organised as a series of pointers tostrings. The end of the token vector is identified by a null pointer.<p>When<i>getsubopt()</i>returns, if *<i>valuep</i> is not a null pointer then the suboption argumentprocessed included a value. The calling program may use this information todetermine if the presence or lack of a value for this suboption is an error.<p>Additionally, when<i>getsubopt()</i>fails to match the suboption argument with the tokens in the<i>tokens</i>array, the calling program should decide if this is an error, or if theunrecognised option should be passed on to another program.</blockquote><h4><a name = "tag_000_005_752"> </a>RETURN VALUE</h4><blockquote>The<i>getsubopt()</i>function returns the index of the matched token string, or -1 if no tokenstrings were matched.</blockquote><h4><a name = "tag_000_005_753"> </a>ERRORS</h4><blockquote>No errors are defined.</blockquote><h4><a name = "tag_000_005_754"> </a>EXAMPLES</h4><blockquote>None.</blockquote><h4><a name = "tag_000_005_755"> </a>APPLICATION USAGE</h4><blockquote>None.</blockquote><h4><a name = "tag_000_005_756"> </a>FUTURE DIRECTIONS</h4><blockquote>None.</blockquote><h4><a name = "tag_000_005_757"> </a>SEE ALSO</h4><blockquote><i><a href="getopt.html">getopt()</a></i>,<i><a href="stdlib.h.html"><stdlib.h></a></i>.</blockquote><hr size=2 noshade><center><font size=2>UNIX ® is a registered Trademark of The Open Group.<br>Copyright © 1997 The Open Group<br> [ <a href="../index.html">Main Index</a> | <a href="../xshix.html">XSH</a> | <a href="../xcuix.html">XCU</a> | <a href="../xbdix.html">XBD</a> | <a href="../cursesix.html">XCURSES</a> | <a href="../xnsix.html">XNS</a> ]</font></center><hr size=2 noshade></body></html>⌨️ 快捷键说明
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