xbd_chap08.html

IEEE 1003.1-2003, Single Unix Specification v3

</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>GET</i></p>
</td>
<td align="left">
<p class="tent"><i>LISTER</i></p>
</td>
<td align="left">
<p class="tent"><i>PAGER</i></p>
</td>
<td align="left">
<p class="tent"><i>VISUAL</i></p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>GFLAGS</i></p>
</td>
<td align="left">
<p class="tent"><i>LOGNAME</i></p>
</td>
<td align="left">
<p class="tent"><i>PATH</i></p>
</td>
<td align="left">
<p class="tent"><i>YACC</i></p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>HISTFILE</i></p>
</td>
<td align="left">
<p class="tent"><i>LPDEST</i></p>
</td>
<td align="left">
<p class="tent"><i>PPID</i></p>
</td>
<td align="left">
<p class="tent"><i>YFLAGS</i></p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>HISTORY</i></p>
</td>
<td align="left">
<p class="tent"><i>MAIL</i></p>
</td>
<td align="left">
<p class="tent"><i>PRINTER</i></p>
</td>
<td align="left">
<p class="tent"><i>&nbsp;</i></p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>HISTSIZE</i></p>
</td>
<td align="left">
<p class="tent"><i>MAILCHECK</i></p>
</td>
<td align="left">
<p class="tent"><i>PROCLANG</i></p>
</td>
<td align="left">
<p class="tent"><i>&nbsp;</i></p>
</td>
</tr>

<tr valign="top">
<td align="left">
<p class="tent"><i>HOME</i></p>
</td>
<td align="left">
<p class="tent"><i>MAILER</i></p>
</td>
<td align="left">
<p class="tent"><i>PROJECTDIR</i></p>
</td>
<td align="left">
<p class="tent"><i>&nbsp;</i></p>
</td>
</tr>
</table>
</center>

<p>If the variables in the following two sections are present in the environment during the execution of an application or utility,
they shall be given the meaning described below. Some are placed into the environment by the implementation at the time the user
logs in; all can be added or changed by the user or any ancestor of the current process. The implementation adds or changes
environment variables named in IEEE&nbsp;Std&nbsp;1003.1-2001 only as specified in IEEE&nbsp;Std&nbsp;1003.1-2001. If they are
defined in the application's environment, the utilities in the Shell and Utilities volume of IEEE&nbsp;Std&nbsp;1003.1-2001 and the
functions in the System Interfaces volume of IEEE&nbsp;Std&nbsp;1003.1-2001 assume they have the specified meaning. Conforming
applications shall not set these environment variables to have meanings other than as described. See <a href=
"../functions/getenv.html"><i>getenv</i>()</a> and the Shell and Utilities volume of IEEE&nbsp;Std&nbsp;1003.1-2001, <a href=
"../utilities/xcu_chap02.html#tag_02_12">Section 2.12, Shell Execution Environment</a> for methods of accessing these
variables.</p>

<h3><a name="tag_08_02"></a>Internationalization Variables</h3>

<p>This section describes environment variables that are relevant to the operation of internationalized interfaces described in
IEEE&nbsp;Std&nbsp;1003.1-2001.</p>

<p>Users may use the following environment variables to announce specific localization requirements to applications. Applications
can retrieve this information using the <a href="../functions/setlocale.html"><i>setlocale</i>()</a> function to initialize the
correct behavior of the internationalized interfaces. The descriptions of the internationalization environment variables describe
the resulting behavior only when the application locale is initialized in this way. The use of the internationalization variables
by utilities described in the Shell and Utilities volume of IEEE&nbsp;Std&nbsp;1003.1-2001 is described in the ENVIRONMENT
VARIABLES section for those utilities in addition to the global effects described in this section.</p>

<dl compact>
<dt><i>LANG</i></dt>

<dd>This variable shall determine the locale category for native language, local customs, and coded character set in the absence of
the <i>LC_ALL</i> and other <i>LC_*</i> ( <i>LC_COLLATE ,</i> <i>LC_CTYPE ,</i> <i>LC_MESSAGES ,</i> <i>LC_MONETARY ,</i>
<i>LC_NUMERIC ,</i> <i>LC_TIME )</i> environment variables. This can be used by applications to determine the language to use for
error messages and instructions, collating sequences, date formats, and so on.</dd>

<dt><i>LC_ALL</i></dt>

<dd>This variable shall determine the values for all locale categories. The value of the <i>LC_ALL</i> environment variable has
precedence over any of the other environment variables starting with <i>LC_</i> ( <i>LC_COLLATE ,</i> <i>LC_CTYPE ,</i>
<i>LC_MESSAGES ,</i> <i>LC_MONETARY ,</i> <i>LC_NUMERIC ,</i> <i>LC_TIME )</i> and the <i>LANG</i> environment variable.</dd>

<dt><i>LC_COLLATE</i></dt>

<dd>This variable shall determine the locale category for character collation. It determines collation information for regular
expressions and sorting, including equivalence classes and multi-character collating elements, in various utilities and the <a
href="../functions/strcoll.html"><i>strcoll</i>()</a> and <a href="../functions/strxfrm.html"><i>strxfrm</i>()</a> functions.
Additional semantics of this variable, if any, are implementation-defined.</dd>

<dt><i>LC_CTYPE</i></dt>

<dd>This variable shall determine the locale category for character handling functions, such as <a href=
"../functions/tolower.html"><i>tolower</i>()</a>, <a href="../functions/toupper.html"><i>toupper</i>()</a>, and <a href=
"../functions/isalpha.html"><i>isalpha</i>()</a>. This environment variable determines the interpretation of sequences of bytes of
text data as characters (for example, single as opposed to multi-byte characters), the classification of characters (for example,
alpha, digit, graph), and the behavior of character classes. Additional semantics of this variable, if any, are
implementation-defined.</dd>

<dt><i>LC_MESSAGES</i></dt>

<dd>This variable shall determine the locale category for processing affirmative and negative responses and the language and
cultural conventions in which messages should be written. <sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src=
"../images/opt-start.gif" alt="[Option Start]" border="0"> &nbsp;It also affects the behavior of the <a href=
"../functions/catopen.html"><i>catopen</i>()</a> function in determining the message catalog. <img src="../images/opt-end.gif" alt=
"[Option End]" border="0"> Additional semantics of this variable, if any, are implementation-defined. The language and cultural
conventions of diagnostic and informative messages whose format is unspecified by IEEE&nbsp;Std&nbsp;1003.1-2001 should be affected
by the setting of <i>LC_MESSAGES .</i></dd>

<dt><i>LC_MONETARY</i></dt>

<dd>This variable shall determine the locale category for monetary-related numeric formatting information. Additional semantics of
this variable, if any, are implementation-defined.</dd>

<dt><i>LC_NUMERIC</i></dt>

<dd>This variable shall determine the locale category for numeric formatting (for example, thousands separator and radix character)
information in various utilities as well as the formatted I/O operations in <a href="../functions/printf.html"><i>printf</i>()</a>
and <a href="../functions/scanf.html"><i>scanf</i>()</a> and the string conversion functions in <a href=
"../functions/strtod.html"><i>strtod</i>()</a>. Additional semantics of this variable, if any, are implementation-defined.</dd>

<dt><i>LC_TIME</i></dt>

<dd>This variable shall determine the locale category for date and time formatting information. It affects the behavior of the time
functions in <a href="../functions/strftime.html"><i>strftime</i>()</a>. Additional semantics of this variable, if any, are
implementation-defined.</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">
This variable shall contain a sequence of templates that the <a href="../functions/catopen.html"><i>catopen</i>()</a> function uses
when attempting to locate message catalogs. Each template consists of an optional prefix, one or more conversion specifications, a
filename, and an optional suffix. 

<p>For example:</p>

<blockquote>
<pre>
<tt>NLSPATH="/system/nlslib/%N.cat"
</tt>
</pre>
</blockquote>

<p>defines that <a href="../functions/catopen.html"><i>catopen</i>()</a> should look for all message catalogs in the directory
<b>/system/nlslib</b>, where the catalog name should be constructed from the <i>name</i> parameter passed to <a href=
"../functions/catopen.html"><i>catopen</i>()</a> ( <tt>%N</tt> ), with the suffix <b>.cat</b>.</p>

<p>Conversion specifications consist of a <tt>'%'</tt> symbol, followed by a single-letter keyword. The following keywords are
currently defined:</p>

<dl compact>
<dt><tt>%N</tt></dt>

<dd>The value of the <i>name</i> parameter passed to <a href="../functions/catopen.html"><i>catopen</i>()</a>.</dd>

<dt><tt>%L</tt></dt>

<dd>The value of the <i>LC_MESSAGES</i> category.</dd>

<dt><tt>%l</tt></dt>

<dd>The <i>language</i> element from the <i>LC_MESSAGES</i> category.</dd>

<dt><tt>%t</tt></dt>

<dd>The <i>territory</i> element from the <i>LC_MESSAGES</i> category.</dd>

<dt><tt>%c</tt></dt>

<dd>The <i>codeset</i> element from the <i>LC_MESSAGES</i> category.</dd>

<dt><tt>%%</tt></dt>

<dd>A single <tt>'%'</tt> character.</dd>
</dl>

<p>An empty string is substituted if the specified value is not currently defined. The separators underscore ( <tt>'_'</tt> ) and
period ( <tt>'.'</tt> ) are not included in the <tt>%t</tt> and <tt>%c</tt> conversion specifications.</p>

<p>Templates defined in <i>NLSPATH</i> are separated by colons ( <tt>':'</tt> ). A leading or two adjacent colons <tt>"::"</tt> is
equivalent to specifying <tt>%N</tt> . For example:</p>

<blockquote>
<pre>
<tt>NLSPATH=":%N.cat:/nlslib/%L/%N.cat"
</tt>
</pre>
</blockquote>

<p>indicates to <a href="../functions/catopen.html"><i>catopen</i>()</a> that it should look for the requested message catalog in
<i>name</i>, <i>name</i><b>.cat</b>, and <b>/nlslib/</b><i>category</i><b>/</b><i>name</i><b>.cat</b>, where <i>category</i> is the
value of the <i>LC_MESSAGES</i> category of the current locale.</p>

<p>Users should not set the <i>NLSPATH</i> variable unless they have a specific reason to override the default system path. Setting
<i>NLSPATH</i> to override the default system path produces undefined results in the standard utilities and in applications with
appropriate privileges. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></p>
</dd>
</dl>

<p>The environment variables <i>LANG ,</i> <i>LC_ALL ,</i> <i>LC_COLLATE ,</i> <i>LC_CTYPE ,</i> <i>LC_MESSAGES ,</i>
<i>LC_MONETARY ,</i> <i>LC_NUMERIC ,</i> <i>LC_TIME ,</i> <sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src=
"../images/opt-start.gif" alt="[Option Start]" border="0"> &nbsp;and <i>NLSPATH</i> <img src="../images/opt-end.gif" alt=
"[Option End]" border="0"> &nbsp;provide for the support of internationalized applications. The standard utilities shall make use
of these environment variables as described in this section and the individual ENVIRONMENT VARIABLES sections for the utilities. If
these variables specify locale categories that are not based upon the same underlying codeset, the results are unspecified.</p>

<p>The values of locale categories shall be determined by a precedence order; the first condition met below determines the
value:</p>

<ol>
<li>
<p>If the <i>LC_ALL</i> environment variable is defined and is not null, the value of <i>LC_ALL</i> shall be used.</p>
</li>

<li>
<p>If the <i>LC_*</i> environment variable ( <i>LC_COLLATE ,</i> <i>LC_CTYPE ,</i> <i>LC_MESSAGES ,</i> <i>LC_MONETARY ,</i>
<i>LC_NUMERIC ,</i> <i>LC_TIME )</i> is defined and is not null, the value of the environment variable shall be used to initialize
the category that corresponds to the environment variable.</p>
</li>

<li>
<p>If the <i>LANG</i> environment variable is defined and is not null, the value of the <i>LANG</i> environment variable shall be
used.</p>
</li>

<li>
<p>If the <i>LANG</i> environment variable is not set or is set to the empty string, the implementation-defined default locale
shall be used.</p>
</li>
</ol>

<p>If the locale value is <tt>"C"</tt> or <tt>"POSIX"</tt> , the POSIX locale shall be used and the standard utilities behave in
accordance with the rules in <a href="xbd_chap07.html#tag_07_02"><i>POSIX Locale</i></a> for the associated category.</p>

<p>If the locale value begins with a slash, it shall be interpreted as the pathname of a file that was created in the output format
used by the <a href="../utilities/localedef.html"><i>localedef</i></a> utility; see OUTPUT FILES under <a href=
"../utilities/localedef.html"><i>localedef</i></a>. Referencing such a pathname shall result in that locale being used for the
indicated category.</p>