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 <p>
 Previous:&nbsp;<a rel="previous" accesskey="p" href="Adding-Severity-Classes.html#Adding-Severity-Classes">Adding Severity Classes</a>,
 Up:&nbsp;<a rel="up" accesskey="u" href="Formatted-Messages.html#Formatted-Messages">Formatted Messages</a>
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 </div>

 <h4 class="subsection">12.22.3 How to use <code>fmtmsg</code> and <code>addseverity</code></h4>

 <p>Here is a simple example program to illustrate the use of the both
 functions described in this section.

 <pre class="smallexample">     #include &lt;fmtmsg.h&gt;

      int
      main (void)
      {
        addseverity (5, "NOTE2");
        fmtmsg (MM_PRINT, "only1field", MM_INFO, "text2", "action2", "tag2");
        fmtmsg (MM_PRINT, "UX:cat", 5, "invalid syntax", "refer to manual",
                "UX:cat:001");
        fmtmsg (MM_PRINT, "label:foo", 6, "text", "action", "tag");
        return 0;
      }
 </pre>
    <p>The second call to <code>fmtmsg</code> illustrates a use of this function as
 it usually occurs on System V systems, which heavily use this function.
 It seems worthwhile to give a short explanation here of how this system
 works on System V.  The value of the
 <var>label</var> field (<code>UX:cat</code>) says that the error occurred in the
 Unix program <code>cat</code>.  The explanation of the error follows and the
 value for the <var>action</var> parameter is <code>"refer to manual"</code>.  One
 could be more specific here, if necessary.  The <var>tag</var> field contains,
 as proposed above, the value of the string given for the <var>label</var>
 parameter, and additionally a unique ID (<code>001</code> in this case).  For
 a GNU environment this string could contain a reference to the
 corresponding node in the Info page for the program.

 <p class="noindent">Running this program without specifying the <code>MSGVERB</code> and
 <code>SEV_LEVEL</code> function produces the following output:

 <pre class="smallexample">     UX:cat: NOTE2: invalid syntax
      TO FIX: refer to manual UX:cat:001
 </pre>
    <p>We see the different fields of the message and how the extra glue (the
 colons and the <code>TO FIX</code> string) are printed.  But only one of the
 three calls to <code>fmtmsg</code> produced output.  The first call does not
 print anything because the <var>label</var> parameter is not in the correct
 form.  The string must contain two fields, separated by a colon
 (see <a href="Printing-Formatted-Messages.html#Printing-Formatted-Messages">Printing Formatted Messages</a>).  The third <code>fmtmsg</code> call
 produced no output since the class with the numeric value <code>6</code> is
 not defined.  Although a class with numeric value <code>5</code> is also not
 defined by default, the call to <code>addseverity</code> introduces it and
 the second call to <code>fmtmsg</code> produces the above output.

    <p>When we change the environment of the program to contain
 <code>SEV_LEVEL=XXX,6,NOTE</code> when running it we get a different result:

 <pre class="smallexample">     UX:cat: NOTE2: invalid syntax
      TO FIX: refer to manual UX:cat:001
      label:foo: NOTE: text
      TO FIX: action tag
 </pre>
    <p>Now the third call to <code>fmtmsg</code> produced some output and we see how
 the string <code>NOTE</code> from the environment variable appears in the
 message.

    <p>Now we can reduce the output by specifying which fields we are
 interested in.  If we additionally set the environment variable
 <code>MSGVERB</code> to the value <code>severity:label:action</code> we get the
 following output:

 <pre class="smallexample">     UX:cat: NOTE2
      TO FIX: refer to manual
      label:foo: NOTE
      TO FIX: action
 </pre>
    <p class="noindent">I.e., the output produced by the <var>text</var> and the <var>tag</var> parameters
 to <code>fmtmsg</code> vanished.  Please also note that now there is no colon
 after the <code>NOTE</code> and <code>NOTE2</code> strings in the output.  This is
 not necessary since there is no more output on this line because the text
 is missing.

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	This file documents the GNU C library.

	This is Edition 0.12, last updated 2007-10-27,
	of `The GNU C Library Reference Manual', for version
	2.8 (Sourcery G++ Lite 2011.03-41).

	Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002,
	2003, 2007, 2008, 2010 Free Software Foundation, Inc.

	Permission is granted to copy, distribute and/or modify this document
	under the terms of the GNU Free Documentation License, Version 1.3 or
	any later version published by the Free Software Foundation; with the
	Invariant Sections being ``Free Software Needs Free Documentation''
	and ``GNU Lesser General Public License'', the Front-Cover texts being
	``A GNU Manual'', and with the Back-Cover Texts as in (a) below. A
	copy of the license is included in the section entitled "GNU Free
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	Previous: <a rel="previous" accesskey="p" href="Adding-Severity-Classes.html#Adding-Severity-Classes">Adding Severity Classes</a>,
	Up: <a rel="up" accesskey="u" href="Formatted-Messages.html#Formatted-Messages">Formatted Messages</a>
	<hr>
	</div>

	<h4 class="subsection">12.22.3 How to use <code>fmtmsg</code> and <code>addseverity</code></h4>

	<p>Here is a simple example program to illustrate the use of the both
	functions described in this section.

	<pre class="smallexample"> #include <fmtmsg.h>

	int
	main (void)
	{
	addseverity (5, "NOTE2");
	fmtmsg (MM_PRINT, "only1field", MM_INFO, "text2", "action2", "tag2");
	fmtmsg (MM_PRINT, "UX:cat", 5, "invalid syntax", "refer to manual",
	"UX:cat:001");
	fmtmsg (MM_PRINT, "label:foo", 6, "text", "action", "tag");
	return 0;
	}
	</pre>
	<p>The second call to <code>fmtmsg</code> illustrates a use of this function as
	it usually occurs on System V systems, which heavily use this function.
	It seems worthwhile to give a short explanation here of how this system
	works on System V. The value of the
	<var>label</var> field (<code>UX:cat</code>) says that the error occurred in the
	Unix program <code>cat</code>. The explanation of the error follows and the
	value for the <var>action</var> parameter is <code>"refer to manual"</code>. One
	could be more specific here, if necessary. The <var>tag</var> field contains,
	as proposed above, the value of the string given for the <var>label</var>
	parameter, and additionally a unique ID (<code>001</code> in this case). For
	a GNU environment this string could contain a reference to the
	corresponding node in the Info page for the program.

	<p class="noindent">Running this program without specifying the <code>MSGVERB</code> and
	<code>SEV_LEVEL</code> function produces the following output:

	<pre class="smallexample"> UX:cat: NOTE2: invalid syntax
	TO FIX: refer to manual UX:cat:001
	</pre>
	<p>We see the different fields of the message and how the extra glue (the
	colons and the <code>TO FIX</code> string) are printed. But only one of the
	three calls to <code>fmtmsg</code> produced output. The first call does not
	print anything because the <var>label</var> parameter is not in the correct
	form. The string must contain two fields, separated by a colon
	(see <a href="Printing-Formatted-Messages.html#Printing-Formatted-Messages">Printing Formatted Messages</a>). The third <code>fmtmsg</code> call
	produced no output since the class with the numeric value <code>6</code> is
	not defined. Although a class with numeric value <code>5</code> is also not
	defined by default, the call to <code>addseverity</code> introduces it and
	the second call to <code>fmtmsg</code> produces the above output.

	<p>When we change the environment of the program to contain
	<code>SEV_LEVEL=XXX,6,NOTE</code> when running it we get a different result:

	<pre class="smallexample"> UX:cat: NOTE2: invalid syntax
	TO FIX: refer to manual UX:cat:001
	label:foo: NOTE: text
	TO FIX: action tag
	</pre>
	<p>Now the third call to <code>fmtmsg</code> produced some output and we see how
	the string <code>NOTE</code> from the environment variable appears in the
	message.

	<p>Now we can reduce the output by specifying which fields we are
	interested in. If we additionally set the environment variable
	<code>MSGVERB</code> to the value <code>severity:label:action</code> we get the
	following output:

	<pre class="smallexample"> UX:cat: NOTE2
	TO FIX: refer to manual
	label:foo: NOTE
	TO FIX: action
	</pre>
	<p class="noindent">I.e., the output produced by the <var>text</var> and the <var>tag</var> parameters
	to <code>fmtmsg</code> vanished. Please also note that now there is no colon
	after the <code>NOTE</code> and <code>NOTE2</code> strings in the output. This is
	not necessary since there is no more output on this line because the text
	is missing.

	</body></html>