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23 <script language="JavaScript" src="../jscript/codes.js"></script><basefont size="3">
24 <center><font size="2">The Open Group Base Specifications Issue 8<br>
25 IEEE Std 1003.1-2024<br>
26 Copyright © 2001-2024 The IEEE and The Open Group</font></center>
27 <hr size="2" noshade>
28 <a name="top" id="top"></a> <a name="unalias" id="unalias"></a> <a name="tag_20_133" id="tag_20_133"></a><!-- unalias -->
29 <h4 class="mansect"><a name="tag_20_133_01" id="tag_20_133_01"></a>NAME</h4>
30 <blockquote>unalias — remove alias definitions</blockquote>
31 <h4 class="mansect"><a name="tag_20_133_02" id="tag_20_133_02"></a>SYNOPSIS</h4>
32 <blockquote class="synopsis">
33 <p><code><tt>unalias</tt> <i>alias-name</i><tt>...<br>
34 <br>
35 unalias -a<br></tt></code></p>
36 </blockquote>
37 <h4 class="mansect"><a name="tag_20_133_03" id="tag_20_133_03"></a>DESCRIPTION</h4>
38 <blockquote>
39 <p>The <i>unalias</i> utility shall remove the definition for each alias name specified. See <a href=
40 "../utilities/V3_chap02.html#tag_19_03_01"><i>2.3.1 Alias Substitution</i></a> . The aliases shall be removed from the current
41 shell execution environment; see <a href="../utilities/V3_chap02.html#tag_19_13"><i>2.13 Shell Execution Environment</i></a> .</p>
42 </blockquote>
43 <h4 class="mansect"><a name="tag_20_133_04" id="tag_20_133_04"></a>OPTIONS</h4>
44 <blockquote>
45 <p>The <i>unalias</i> utility shall conform to XBD <a href="../basedefs/V1_chap12.html#tag_12_02"><i>12.2 Utility Syntax
46 Guidelines</i></a> .</p>
47 <p>The following option shall be supported:</p>
48 <dl compact>
49 <dd></dd>
50 <dt><b>-a</b></dt>
51 <dd>Remove all alias definitions from the current shell execution environment.</dd>
52 </dl>
53 </blockquote>
54 <h4 class="mansect"><a name="tag_20_133_05" id="tag_20_133_05"></a>OPERANDS</h4>
55 <blockquote>
56 <p>The following operand shall be supported:</p>
57 <dl compact>
58 <dd></dd>
59 <dt><i>alias-name</i></dt>
60 <dd>The name of an alias to be removed.</dd>
61 </dl>
62 </blockquote>
63 <h4 class="mansect"><a name="tag_20_133_06" id="tag_20_133_06"></a>STDIN</h4>
64 <blockquote>
65 <p>Not used.</p>
66 </blockquote>
67 <h4 class="mansect"><a name="tag_20_133_07" id="tag_20_133_07"></a>INPUT FILES</h4>
68 <blockquote>
69 <p>None.</p>
70 </blockquote>
71 <h4 class="mansect"><a name="tag_20_133_08" id="tag_20_133_08"></a>ENVIRONMENT VARIABLES</h4>
72 <blockquote>
73 <p>The following environment variables shall affect the execution of <i>unalias</i>:</p>
74 <dl compact>
75 <dd></dd>
76 <dt><i>LANG</i></dt>
77 <dd>Provide a default value for the internationalization variables that are unset or null. (See XBD <a href=
78 "../basedefs/V1_chap08.html#tag_08_02"><i>8.2 Internationalization Variables</i></a> for the precedence of internationalization
79 variables used to determine the values of locale categories.)</dd>
80 <dt><i>LC_ALL</i></dt>
81 <dd>If set to a non-empty string value, override the values of all the other internationalization variables.</dd>
82 <dt><i>LC_CTYPE</i></dt>
83 <dd>Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as
84 opposed to multi-byte characters in arguments).</dd>
85 <dt><i>LC_MESSAGES</i></dt>
86 <dd><br>
87 Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error.</dd>
88 <dt><i>NLSPATH</i></dt>
89 <dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0">
90 Determine the location of messages objects and message catalogs. <img src="../images/opt-end.gif" alt="[Option End]" border=
91 "0"></dd>
92 </dl>
93 </blockquote>
94 <h4 class="mansect"><a name="tag_20_133_09" id="tag_20_133_09"></a>ASYNCHRONOUS EVENTS</h4>
95 <blockquote>
96 <p>Default.</p>
97 </blockquote>
98 <h4 class="mansect"><a name="tag_20_133_10" id="tag_20_133_10"></a>STDOUT</h4>
99 <blockquote>
100 <p>Not used.</p>
101 </blockquote>
102 <h4 class="mansect"><a name="tag_20_133_11" id="tag_20_133_11"></a>STDERR</h4>
103 <blockquote>
104 <p>The standard error shall be used only for diagnostic messages.</p>
105 </blockquote>
106 <h4 class="mansect"><a name="tag_20_133_12" id="tag_20_133_12"></a>OUTPUT FILES</h4>
107 <blockquote>
108 <p>None.</p>
109 </blockquote>
110 <h4 class="mansect"><a name="tag_20_133_13" id="tag_20_133_13"></a>EXTENDED DESCRIPTION</h4>
111 <blockquote>
112 <p>None.</p>
113 </blockquote>
114 <h4 class="mansect"><a name="tag_20_133_14" id="tag_20_133_14"></a>EXIT STATUS</h4>
115 <blockquote>
116 <p>The following exit values shall be returned:</p>
117 <dl compact>
118 <dd></dd>
119 <dt> 0</dt>
120 <dd>Successful completion.</dd>
121 <dt>>0</dt>
122 <dd>One of the <i>alias-name</i> operands specified did not represent a valid alias definition, or an error occurred.</dd>
123 </dl>
124 </blockquote>
125 <h4 class="mansect"><a name="tag_20_133_15" id="tag_20_133_15"></a>CONSEQUENCES OF ERRORS</h4>
126 <blockquote>
127 <p>Default.</p>
128 </blockquote>
129 <hr>
130 <div class="box"><em>The following sections are informative.</em></div>
131 <h4 class="mansect"><a name="tag_20_133_16" id="tag_20_133_16"></a>APPLICATION USAGE</h4>
132 <blockquote>
133 <p>This utility is required to be intrinsic. See <a href="../utilities/V3_chap01.html#tag_18_07"><i>1.7 Intrinsic Utilities</i></a>
134 for details.</p>
135 <p>Since <i>unalias</i> affects the current shell execution environment, it is generally provided as a shell regular built-in.</p>
136 </blockquote>
137 <h4 class="mansect"><a name="tag_20_133_17" id="tag_20_133_17"></a>EXAMPLES</h4>
138 <blockquote>
139 <p>None.</p>
140 </blockquote>
141 <h4 class="mansect"><a name="tag_20_133_18" id="tag_20_133_18"></a>RATIONALE</h4>
142 <blockquote>
143 <p>The <i>unalias</i> description is based on that from historical KornShell implementations. Known differences exist between that
144 and the C shell. The KornShell version was adopted to be consistent with all the other KornShell features in this volume of
145 POSIX.1-2024, such as command line editing.</p>
146 <p>The <b>-a</b> option is the equivalent of the <i>unalias</i> * form of the C shell and is provided to address security concerns
147 about unknown aliases entering the environment of a user (or application) through the allowable implementation-defined predefined
148 alias route or as a result of an <i>ENV</i> file. (Although <i>unalias</i> could be used to simplify the "secure" shell script
149 shown in the <a href="../utilities/command.html"><i>command</i></a> rationale, it does not obviate the need to quote all command
150 names. An initial call to <i>unalias</i> <b>-a</b> would have to be quoted in case there was an alias for <i>unalias</i>.)</p>
151 </blockquote>
152 <h4 class="mansect"><a name="tag_20_133_19" id="tag_20_133_19"></a>FUTURE DIRECTIONS</h4>
153 <blockquote>
154 <p>None.</p>
155 </blockquote>
156 <h4 class="mansect"><a name="tag_20_133_20" id="tag_20_133_20"></a>SEE ALSO</h4>
157 <blockquote>
158 <p><a href="../utilities/V3_chap02.html#tag_19"><i>2. Shell Command Language</i></a> , <a href=
159 "../utilities/alias.html#"><i>alias</i></a></p>
160 <p>XBD <a href="../basedefs/V1_chap08.html#tag_08"><i>8. Environment Variables</i></a> , <a href=
161 "../basedefs/V1_chap12.html#tag_12_02"><i>12.2 Utility Syntax Guidelines</i></a></p>
162 </blockquote>
163 <h4 class="mansect"><a name="tag_20_133_21" id="tag_20_133_21"></a>CHANGE HISTORY</h4>
164 <blockquote>
165 <p>First released in Issue 4.</p>
166 </blockquote>
167 <h4 class="mansect"><a name="tag_20_133_22" id="tag_20_133_22"></a>Issue 6</h4>
168 <blockquote>
169 <p>This utility is marked as part of the User Portability Utilities option.</p>
170 </blockquote>
171 <h4 class="mansect"><a name="tag_20_133_23" id="tag_20_133_23"></a>Issue 7</h4>
172 <blockquote>
173 <p>The <i>unalias</i> utility is moved from the User Portability Utilities option to the Base. User Portability Utilities is now an
174 option for interactive utilities.</p>
175 </blockquote>
176 <h4 class="mansect"><a name="tag_20_133_24" id="tag_20_133_24"></a>Issue 8</h4>
177 <blockquote>
178 <p>Austin Group Defect 854 is applied, adding a note to the APPLICATION USAGE section that this utility is required to be
179 intrinsic.</p>
180 <p>Austin Group Defect 1122 is applied, changing the description of <i>NLSPATH .</i></p>
181 </blockquote>
182 <div class="box"><em>End of informative text.</em></div>
183 <hr>
184 <p> </p>
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