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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy, see www.w3.org"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 --><!-- Copyright (c) 2001-2003 The Open Group, All Rights Reserved --><title>uudecode</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="uudecode"></a> <a name="tag_04_162"></a><!-- uudecode --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2003 Edition<br>Copyright © 2001-2003 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_04_162_01"></a>NAME</h4><blockquote>uudecode - decode a binary file</blockquote><h4><a name="tag_04_162_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('UP')">UP</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> uudecode</tt> <b>[</b><tt>-o</tt> <i>outfile</i><b>][</b><i>file</i><b>]</b><tt><img src="../images/opt-end.gif" alt="[Option End]" border="0"></tt></code></div></blockquote><h4><a name="tag_04_162_03"></a>DESCRIPTION</h4><blockquote><p>The <i>uudecode</i> utility shall read a file, or standard input if no file is specified, that includes data created by the <ahref="../utilities/uuencode.html"><i>uuencode</i></a> utility. The <i>uudecode</i> utility shall scan the input file, searching fordata compatible with one of the formats specified in <a href="../utilities/uuencode.html"><i>uuencode</i></a>, and attempt tocreate or overwrite the file described by the data (or overridden by the <b>-o</b> option). The pathname shall be contained in thedata or specified by the <b>-o</b> option. The file access permission bits and contents for the file to be produced shall becontained in that data. The mode bits of the created file (other than standard output) shall be set from the file access permissionbits contained in the data; that is, other attributes of the mode, including the file mode creation mask (see <a href="umask.html"><i>umask</i>()</a> ), shall not affect the file being produced.</p><p>If the pathname of the file to be produced exists, and the user does not have write permission on that file, <i>uudecode</i>shall terminate with an error. If the pathname of the file to be produced exists, and the user has write permission on that file,the existing file shall be overwritten.</p><p>If the input data was produced by <a href="../utilities/uuencode.html"><i>uuencode</i></a> on a system with a different numberof bits per byte than on the target system, the results of <i>uudecode</i> are unspecified.</p></blockquote><h4><a name="tag_04_162_04"></a>OPTIONS</h4><blockquote><p>The <i>uudecode</i> utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/xbd_chap12.html#tag_12_02">Section 12.2, Utility Syntax Guidelines</a>.</p><p>The following option shall be supported by the implementation:</p><dl compact><dt><b>-o </b> <i>outfile</i></dt><dd>A pathname of a file that shall be used instead of any pathname contained in the input data. Specifying an <i>outfile</i>option-argument of <b>/dev/stdout</b> shall indicate standard output.</dd></dl></blockquote><h4><a name="tag_04_162_05"></a>OPERANDS</h4><blockquote><p>The following operand shall be supported:</p><dl compact><dt><i>file</i></dt><dd>The pathname of a file containing the output of <a href="../utilities/uuencode.html"><i>uuencode</i></a>.</dd></dl></blockquote><h4><a name="tag_04_162_06"></a>STDIN</h4><blockquote><p>See the INPUT FILES section.</p></blockquote><h4><a name="tag_04_162_07"></a>INPUT FILES</h4><blockquote><p>The input files shall be files containing the output of <a href="../utilities/uuencode.html"><i>uuencode</i></a>.</p></blockquote><h4><a name="tag_04_162_08"></a>ENVIRONMENT VARIABLES</h4><blockquote><p>The following environment variables shall affect the execution of <i>uudecode</i>:</p><dl compact><dt><i>LANG</i></dt><dd>Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/xbd_chap08.html#tag_08_02">Section 8.2, Internationalization Variables</a> forthe precedence of internationalization variables used to determine the values of locale categories.)</dd><dt><i>LC_ALL</i></dt><dd>If set to a non-empty string value, override the values of all the other internationalization variables.</dd><dt><i>LC_CTYPE</i></dt><dd>Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte asopposed to multi-byte characters in arguments and input files).</dd><dt><i>LC_MESSAGES</i></dt><dd>Determine the locale that should be used to affect the format and contents of diagnostic messages written to standarderror.</dd><dt><i>NLSPATH</i></dt><dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0">Determine the location of message catalogs for the processing of <i>LC_MESSAGES .</i> <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd></dl></blockquote><h4><a name="tag_04_162_09"></a>ASYNCHRONOUS EVENTS</h4><blockquote><p>Default.</p></blockquote><h4><a name="tag_04_162_10"></a>STDOUT</h4><blockquote><p>If the file data header encoded by <a href="../utilities/uuencode.html"><i>uuencode</i></a> is <b>-</b> or <b>/dev/stdout</b>,or the <b>-o</b> <b>/dev/stdout</b> option overrides the file data, the standard output shall be in the same format as the fileoriginally encoded by <a href="../utilities/uuencode.html"><i>uuencode</i></a>. Otherwise, the standard output shall not beused.</p></blockquote><h4><a name="tag_04_162_11"></a>STDERR</h4><blockquote><p>The standard error shall be used only for diagnostic messages.</p></blockquote><h4><a name="tag_04_162_12"></a>OUTPUT FILES</h4><blockquote><p>The output file shall be in the same format as the file originally encoded by <a href="../utilities/uuencode.html"><i>uuencode</i></a>.</p></blockquote><h4><a name="tag_04_162_13"></a>EXTENDED DESCRIPTION</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_162_14"></a>EXIT STATUS</h4><blockquote><p>The following exit values shall be returned:</p><dl compact><dt> 0</dt><dd>Successful completion.</dd><dt>>0</dt><dd>An error occurred.</dd></dl></blockquote><h4><a name="tag_04_162_15"></a>CONSEQUENCES OF ERRORS</h4><blockquote><p>Default.</p></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_04_162_16"></a>APPLICATION USAGE</h4><blockquote><p>The user who is invoking <i>uudecode</i> must have write permission on any file being created.</p><p>The output of <a href="../utilities/uuencode.html"><i>uuencode</i></a> is essentially an encoded bit stream that is notcognizant of byte boundaries. It is possible that a 9-bit byte target machine can process input from an 8-bit source, if it isaware of the requirement, but the reverse is unlikely to be satisfying. Of course, the only data that is meaningful for such atransfer between architectures is generally character data.</p></blockquote><h4><a name="tag_04_162_17"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_162_18"></a>RATIONALE</h4><blockquote><p>Input files are not necessarily text files, as stated by an early proposal. Although the <a href="../utilities/uuencode.html"><i>uuencode</i></a> output is a text file, that output could have been wrapped within another file ormail message that is not a text file.</p><p>The <b>-o</b> option is not historical practice, but was added at the request of WG15 so that the user could override the targetpathname without having to edit the input data itself.</p><p>In early drafts, the [ <b>-o</b> <i>outfile</i>] option-argument allowed the use of <b>-</b> to mean standard output. The symbol<b>-</b> has only been used previously in IEEE Std 1003.1-2001 as a standard input indicator. The developers of thestandard did not wish to overload the meaning of <b>-</b> in this manner. The <b>/dev/stdout</b> concept exists on most modernsystems. The <b>/dev/stdout</b> syntax does not refer to a new special file. It is just a magic cookie to specify standardoutput.</p></blockquote><h4><a name="tag_04_162_19"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_162_20"></a>SEE ALSO</h4><blockquote><p><a href="umask.html"><i>umask</i>()</a> , <a href="uuencode.html"><i>uuencode</i></a></p></blockquote><h4><a name="tag_04_162_21"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 4.</p></blockquote><h4><a name="tag_04_162_22"></a>Issue 6</h4><blockquote><p>This utility is marked as part of the User Portability Utilities option.</p><p>The <b>-o</b> <i>outfile</i> option is added, as specified in the IEEE P1003.2b draft standard.</p><p>The normative text is reworded to avoid use of the term "must" for application requirements.</p></blockquote><div class="box"><em>End of informative text.</em></div><hr><hr size="2" noshade><center><font size="2"><!--footer start-->UNIX ® is a registered Trademark of The Open Group.<br>POSIX ® is a registered Trademark of The IEEE.<br>[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href="../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>]</font></center><!--footer end--><hr size="2" noshade></body></html>⌨️ 快捷键说明
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