glob.html

IEEE 1003.1-2003, Single Unix Specification v3

</li>

<li>
<p>The <i>eerrno</i> argument is the value of <i>errno</i> from the failure, as set by <a href=
"../functions/opendir.html"><i>opendir</i>()</a>, <a href="../functions/readdir.html"><i>readdir</i>()</a>, or <a href=
"../functions/stat.html"><i>stat</i>()</a>. (Other values may be used to report other errors not explicitly documented for those
functions.)</p>
</li>
</ol>

<p>If (<i>*errfunc</i>()) is called and returns non-zero, or if the GLOB_ERR flag is set in <i>flags</i>, <i>glob</i>() shall stop
the scan and return GLOB_ABORTED after setting <i>gl_pathc</i> and <i>gl_pathv</i> in <i>pglob</i> to reflect the paths already
scanned. If GLOB_ERR is not set and either <i>errfunc</i> is a null pointer or (<i>*errfunc</i>()) returns 0, the error shall be
ignored.</p>

<p>The <i>glob</i>() function shall not fail because of large files.</p>
</blockquote>

<h4><a name="tag_03_260_04"></a>RETURN VALUE</h4>

<blockquote>
<p>Upon successful completion, <i>glob</i>() shall return 0. The argument <i>pglob</i>-&gt;<i>gl_pathc</i> shall return the number
of matched pathnames and the argument <i>pglob</i>-&gt;<i>gl_pathv</i> shall contain a pointer to a null-terminated list of matched
and sorted pathnames. However, if <i>pglob</i>-&gt;<i>gl_pathc</i> is 0, the content of <i>pglob</i>-&gt;<i>gl_pathv</i> is
undefined.</p>

<p>The <i>globfree</i>() function shall not return a value.</p>

<p>If <i>glob</i>() terminates due to an error, it shall return one of the non-zero constants defined in <a href=
"../basedefs/glob.h.html"><i>&lt;glob.h&gt;</i></a>. The arguments <i>pglob</i>-&gt;<i>gl_pathc</i> and
<i>pglob</i>-&gt;<i>gl_pathv</i> are still set as defined above.</p>
</blockquote>

<h4><a name="tag_03_260_05"></a>ERRORS</h4>

<blockquote>
<p>The <i>glob</i>() function shall fail and return the corresponding value if:</p>

<dl compact>
<dt>GLOB_ABORTED</dt>

<dd>The scan was stopped because GLOB_ERR was set or (<i>*errfunc</i>()) returned non-zero.</dd>

<dt>GLOB_NOMATCH</dt>

<dd>The pattern does not match any existing pathname, and GLOB_NOCHECK was not set in flags.</dd>

<dt>GLOB_NOSPACE</dt>

<dd>An attempt to allocate memory failed.</dd>
</dl>
</blockquote>

<hr>
<div class="box"><em>The following sections are informative.</em></div>

<h4><a name="tag_03_260_06"></a>EXAMPLES</h4>

<blockquote>
<p>One use of the GLOB_DOOFFS flag is by applications that build an argument list for use with <a href=
"../functions/execv.html"><i>execv</i>()</a>, <a href="../functions/execve.html"><i>execve</i>()</a>, or <a href=
"../functions/execvp.html"><i>execvp</i>()</a>. Suppose, for example, that an application wants to do the equivalent of:</p>

<pre>
<tt>ls -l *.c
</tt>
</pre>

<p>but for some reason:</p>

<pre>
<tt>system("ls -l *.c")
</tt>
</pre>

<p>is not acceptable. The application could obtain approximately the same result using the sequence:</p>

<pre>
<tt>globbuf.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &amp;globbuf);
globbuf.gl_pathv[0] = "ls";
globbuf.gl_pathv[1] = "-l";
execvp("ls", &amp;globbuf.gl_pathv[0]);
</tt>
</pre>

<p>Using the same example:</p>

<pre>
<tt>ls -l *.c *.h
</tt>
</pre>

<p>could be approximately simulated using GLOB_APPEND as follows:</p>

<pre>
<tt>globbuf.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &amp;globbuf);
glob("*.h", GLOB_DOOFFS|GLOB_APPEND, NULL, &amp;globbuf);
...
</tt>
</pre>
</blockquote>

<h4><a name="tag_03_260_07"></a>APPLICATION USAGE</h4>

<blockquote>
<p>This function is not provided for the purpose of enabling utilities to perform pathname expansion on their arguments, as this
operation is performed by the shell, and utilities are explicitly not expected to redo this. Instead, it is provided for
applications that need to do pathname expansion on strings obtained from other sources, such as a pattern typed by a user or read
from a file.</p>

<p>If a utility needs to see if a pathname matches a given pattern, it can use <a href=
"../functions/fnmatch.html"><i>fnmatch</i>()</a>.</p>

<p>Note that <i>gl_pathc</i> and <i>gl_pathv</i> have meaning even if <i>glob</i>() fails. This allows <i>glob</i>() to report
partial results in the event of an error. However, if <i>gl_pathc</i> is 0, <i>gl_pathv</i> is unspecified even if <i>glob</i>()
did not return an error.</p>

<p>The GLOB_NOCHECK option could be used when an application wants to expand a pathname if wildcards are specified, but wants to
treat the pattern as just a string otherwise. The <a href="../utilities/sh.html"><i>sh</i></a> utility might use this for
option-arguments, for example.</p>

<p>The new pathnames generated by a subsequent call with GLOB_APPEND are not sorted together with the previous pathnames. This
mirrors the way that the shell handles pathname expansion when multiple expansions are done on a command line.</p>

<p>Applications that need tilde and parameter expansion should use <a href="../functions/wordexp.html"><i>wordexp</i>()</a>.</p>
</blockquote>

<h4><a name="tag_03_260_08"></a>RATIONALE</h4>

<blockquote>
<p>It was claimed that the GLOB_DOOFFS flag is unnecessary because it could be simulated using:</p>

<pre>
<tt>new = (char **)malloc((n + pglob-&gt;gl_pathc + 1)
       * sizeof(char *));
(void) memcpy(new+n, pglob-&gt;gl_pathv,
       pglob-&gt;gl_pathc * sizeof(char *));
(void) memset(new, 0, n * sizeof(char *));
free(pglob-&gt;gl_pathv);
pglob-&gt;gl_pathv = new;
</tt>
</pre>

<p>However, this assumes that the memory pointed to by <i>gl_pathv</i> is a block that was separately created using <a href=
"../functions/malloc.html"><i>malloc</i>()</a>. This is not necessarily the case. An application should make no assumptions about
how the memory referenced by fields in <i>pglob</i> was allocated. It might have been obtained from <a href=
"../functions/malloc.html"><i>malloc</i>()</a> in a large chunk and then carved up within <i>glob</i>(), or it might have been
created using a different memory allocator. It is not the intent of the standard developers to specify or imply how the memory used
by <i>glob</i>() is managed.</p>

<p>The GLOB_APPEND flag would be used when an application wants to expand several different patterns into a single list.</p>
</blockquote>

<h4><a name="tag_03_260_09"></a>FUTURE DIRECTIONS</h4>

<blockquote>
<p>None.</p>
</blockquote>

<h4><a name="tag_03_260_10"></a>SEE ALSO</h4>

<blockquote>
<p><a href="exec.html"><i><a href="../functions/exec.html">exec</a></i>()</a> , <a href="fnmatch.html"><i>fnmatch</i>()</a> , <a
href="opendir.html"><i>opendir</i>()</a> , <a href="readdir.html"><i>readdir</i>()</a> , <a href="stat.html"><i>stat</i>()</a> , <a
href="wordexp.html"><i>wordexp</i>()</a> , the Base Definitions volume of IEEE&nbsp;Std&nbsp;1003.1-2001, <a href=
"../basedefs/glob.h.html"><i>&lt;glob.h&gt;</i></a>, the Shell and Utilities volume of IEEE&nbsp;Std&nbsp;1003.1-2001</p>
</blockquote>

<h4><a name="tag_03_260_11"></a>CHANGE HISTORY</h4>

<blockquote>
<p>First released in Issue 4. Derived from the ISO&nbsp;POSIX-2 standard.</p>
</blockquote>

<h4><a name="tag_03_260_12"></a>Issue 5</h4>

<blockquote>
<p>Moved from POSIX2 C-language Binding to BASE.</p>
</blockquote>

<h4><a name="tag_03_260_13"></a>Issue 6</h4>

<blockquote>
<p>The DESCRIPTION is updated to avoid use of the term &quot;must&quot; for application requirements.</p>

<p>The <b>restrict</b> keyword is added to the <i>glob</i>() prototype for alignment with the ISO/IEC&nbsp;9899:1999 standard.</p>
</blockquote>

<div class="box"><em>End of informative text.</em></div>

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