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<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
<title>opendir()--Open Directory</title>
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<h2>opendir()--Open Directory</h2>
<div class="box" style="width: 60%;">
<br>
&nbsp;&nbsp;Syntax<br>
<pre>
#include &lt;sys/types.h&gt;
#include &lt;dirent.h&gt;
DIR *opendir(const char <em>*dirname</em>);
</pre>
&nbsp;&nbsp;Service Program Name: QP0LLIB1<br>
<!-- iddvc RMBR -->
<br>
&nbsp;&nbsp;Default Public Authority: *USE<br>
<!-- iddvc RMBR -->
<br>
&nbsp;&nbsp;Threadsafe: Conditional; see <a href="#USAGE_NOTES">Usage Notes</a>.<br>
<!-- iddvc RMBR -->
<br>
</div>
<p>The <strong>opendir()</strong> function opens a directory so that it can be
read with the <strong>readdir()</strong> function. The variable <em>
dirname</em> is a string giving the name of the directory to open. If the last
component of <em>dirname</em> is a symbolic link, <strong>opendir()</strong>
follows the symbolic link. As a result, the directory that the symbolic link
refers to is opened. The functions <strong>readdir()</strong>, <strong>
rewinddir()</strong>, and <strong>closedir()</strong> can be called after a
successful call to <strong>opendir()</strong>. The first <strong>
readdir()</strong> call reads the first entry in the directory.</p>
<p>Names returned on calls to <strong>readdir()</strong> are returned in the
CCSID (coded character set identifier) in effect for the current job at the
time this <strong>opendir()</strong> function is called. If the CCSID of the
job is 65535, the default CCSID of the job is used. See <a href="opendiru.htm">
QlgOpendir()--Open Directory</a> for specifying a different CCSID.</p>
<br>
<h3>Parameters</h3>
<dl>
<dt><strong><em>dirname</em></strong></dt>
<dd>(Input) A pointer to the null-terminated path name of the directory to be
opened.
<p>This parameter is assumed to be represented in the CCSID currently in effect
for the job. If the CCSID of the job is 65535, this parameter is assumed to be
represented in the default CCSID of the job.</p>
<p>See <a href="opendiru.htm">QlgOpendir()--Open Directory</a> for a
description and an example of supplying the <em>dirname</em> in any CCSID.</p>
</dd>
</dl>
<br>
<h3>Authorities</h3>
<p><strong>Note:</strong> Adopted authority is not used.</p>
<p><strong><a name="TBLAOPENDI">Authorization required for
opendir()</a></strong></p>
<table border cellpadding="5" width="80%">
<tr>
<th align="left" valign="bottom">Object Referred to</th>
<th align="center" valign="bottom">Authority Required</th>
<th align="left" valign="bottom">errno</th>
</tr>
<tr>
<td align="left" valign="top" width="75%">Each directory in the path name
preceding the directory to be opened</td>
<td align="center" valign="top" width="15%">*X</td>
<td align="left" valign="top" width="10%">EACCES</td>
</tr>
<tr>
<td align="left" valign="top">The directory to be opened</td>
<td align="center" valign="top">*R</td>
<td align="left" valign="top">EACCES</td>
</tr>
</table>
<br>
<h3>Return Value</h3>
<dl compact>
<dt><em>value</em></dt>
<dd><strong>opendir()</strong> was successful. The value returned is a pointer
to a <samp>DIR</samp>, representing an open directory stream. This <samp>DIR</samp>
describes the directory and is used in subsequent operations on the directory
using the <strong>readdir()</strong>, <strong>rewinddir()</strong>, and
<strong>closedir()</strong> functions.</dd>
<dt><em>NULL pointer</em></dt>
<dd><strong>opendir()</strong> was not successful. The <em>errno</em> global
variable is set to indicate the error.</dd>
</dl>
<br>
<h3>Error Conditions</h3>
<p>If <strong>opendir()</strong> is not successful, <em>errno</em> usually
indicates one of the following errors. Under some conditions, <em>errno</em>
could indicate an error other than those listed here.</p>
<table cellpadding="5">
<!-- cols="25 75" -->
<tr>
<th align="left" valign="bottom">Error condition</th>
<th align="left" valign="bottom">Additional information</th>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EACCES">EACCES</a>]</em></td>
<td align="left" valign="top">
<p>If you are accessing a remote file through the Network File System, update
operations to file permissions at the server are not reflected at the client
until updates to data that is stored locally by the Network File System take
place. (Several options on the Add Mounted File System (ADDMFS) command
determine the time between refresh operations of local data.) Access to a
remote file may also fail due to different mappings of user IDs (UID) or group
IDs (GID) on the local and remote systems.</p>
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EAGAIN">EAGAIN</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EBADFID">EBADFID</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EBADNAME">EBADNAME</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EBUSY">EBUSY</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ECONVERT">ECONVERT</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EDAMAGE">EDAMAGE</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EEXIST">EEXIST</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EFAULT">EFAULT</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EFILECVT">EFILECVT</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EINTR">EINTR</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EINVAL">EINVAL</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EIO">EIO</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EJRNDAMAGE">EJRNDAMAGE</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EJRNENTTOOLONG">EJRNENTTOOLONG</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EJRNINACTIVE">EJRNINACTIVE</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EJRNRCVSPC">EJRNRCVSPC</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ELOOP">ELOOP</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EMFILE">EMFILE</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENAMETOOLONG">ENAMETOOLONG</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENEWJRN">ENEWJRN</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENEWJRNRCV">ENEWJRNRCV</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENFILE">ENFILE</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOENT">ENOENT</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOMEM">ENOMEM</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOSPC">ENOSPC</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOTAVAIL">ENOTAVAIL</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOTDIR">ENOTDIR</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOTSAFE">ENOTSAFE</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENOTSUP">ENOTSUP</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EROOBJ">EROOBJ</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ESTALE">ESTALE</a>]</em></td>
<td align="left" valign="top">
<p>If you are accessing a remote file through the Network File System, the file
may have been deleted at the server.</p>
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EUNKNOWN">EUNKNOWN</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
</table>
<p>If interaction with a file server is required to access the object, <em>
errno</em> could indicate one of the following errors:</p>
<table cellpadding="5">
<!-- cols="25 75" -->
<tr>
<th align="left" valign="bottom">Error condition</th>
<th align="left" valign="bottom">Additional information</th>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EADDRNOTAVAIL">EADDRNOTAVAIL</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ECONNABORTED">ECONNABORTED</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ECONNREFUSED">ECONNREFUSED</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ECONNRESET">ECONNRESET</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EHOSTDOWN">EHOSTDOWN</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EHOSTUNREACH">EHOSTUNREACH</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENETDOWN">ENETDOWN</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENETRESET">ENETRESET</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ENETUNREACH">ENETUNREACH</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ESTALE">ESTALE</a>]</em></td>
<td align="left" valign="top">
<p>If you are accessing a remote file through the Network File System, the file
may have been deleted at the server.</p>
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#ETIMEDOUT">ETIMEDOUT</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
<tr>
<td align="left" valign="top">
<em>[<a href="unix14.htm#EUNATCH">EUNATCH</a>]</em></td>
<td align="left" valign="top">
&nbsp;
</td>
</tr>
</table>
<br>
<br>
<h3>Error Messages</h3>
<p>The following messages may be sent from this function:</p>
<table width="100%">
<tr>
<th align="left" valign="top">Message ID</th>
<th align="left" valign="top">Error Message Text</th>
</tr>
<tr>
<td width="15%" valign="top">CPE3418 E</td>
<td width="85%" valign="top">Possible APAR condition or hardware failure.</td>
</tr>
<tr>
<td valign="top">CPFA0D4 E</td>
<td valign="top">File system error occurred. Error number &amp;1.</td>
</tr>
<tr>
<td valign="top">CPF3CF2 E</td>
<td valign="top">Error(s) occurred during running of &amp;1 API.</td>
</tr>
<tr>
<td valign="top">CPF9872 E</td>
<td valign="top">Program or service program &amp;1 in library &amp;2 ended.
Reason code &amp;3.</td>
</tr>
</table>
<br>
<h3><a name="USAGE_NOTES">Usage Notes</a></h3>
<ol type="1">
<li>This function will fail with error code [ENOTSAFE] when all the following
conditions are true:<br>
<br>
<ul>
<li>Where multiple threads exist in the job.<br>
</li>
<li>The object on which this function is operating resides in a file system
that is not threadsafe. Only the following file systems are threadsafe for this
function:<br>
<br>
<ul>
<li>"Root" (/)</li>
<li>QOpenSys</li>
<li>User-defined</li>
<li>QNTC</li>
<li>QSYS.LIB</li>
<li>Independent ASP QSYS.LIB</li>
<li>QOPT</li>
<li>Network File System</li>
<li>QFileSvr.400</li>
</ul>
</li>
</ul>
<br>
</li>
<li>The <strong>opendir()</strong> function uses a file descriptor for each
open directory. Applications are limited to opening no more than OPEN_MAX files
and directories, and are subject to receiving the [EMFILE] and [ENFILE] errors
when too many file descriptors are in use. See the <strong>sysconf()</strong>
function for a description of OPEN_MAX.
<p>The file descriptor that is used by <strong>opendir()</strong> will not be
inherited in a child process that is created by the <strong>spawn()</strong> or
<strong>spawnp()</strong> API.</p>
</li>
<li><p><strong>opendir()</strong> may allocate memory from the user's heap.</p>
</li>
<li><p>Files that are added to the directory after the first call to <strong>
readdir()</strong> following an <strong>opendir()</strong> or <strong>
rewinddir()</strong> may not be returned on calls to <strong>
readdir()</strong>, and files that are removed may still be returned on calls
to <strong>readdir()</strong>.</p>
</li>
<li>QDLS File System Differences
<p>QDLS updates the access time on <strong>opendir()</strong>.</p>
<br>
</li>
<li>QOPT File System Differences
<p>If the directory exists on a volume formatted in Universal Disk Format
(UDF), the authorization that is checked for the directory and preceding
directories in the path name follows the rules described in <a href=
"#TBLAOPENDI">Authorization required for opendir()</a>. If the directory exists
on a volume formatted in some other media format, no authorization checks are
made on the directory being opened and each directory in the path name. The
volume authorization list is checked for *USE authority regardless of the
volume media format.</p>
</li>
</ol>
<br>
<h3>Related Information</h3>
<ul>
<li>The &lt;<strong>sys/types.h</strong>&gt; file (see <a href="unix13.htm">
Header Files for UNIX-Type Functions</a>)</li>
<li>The &lt;<strong>dirent.h</strong>&gt; file (see <a href="unix13.htm">Header
Files for UNIX-Type Functions</a>)</li>
<li><a href="closedir.htm">closedir()</a>--Close Directory</li>
<li><a href="opendiru.htm">QlgOpendir()</a>--Open Directory</li>
<li><a href="readdirr.htm">readdir()</a>--Read Directory Entry</li>
<li><a href="readdirr.htm">readdir_r()</a>--Read Directory Entry</li>
<li><a href="readdirrts64.htm">readdir_r_ts64()</a>--Read Directory Entry</li>
<li><a href="rewinddi.htm">rewinddir()</a>--Reset Directory Stream to
Beginning</li>
<li><a href="spawn.htm">spawn()</a>--Spawn Process</li>
<li><a href="spawn.htm">spawnp()</a>--Spawn Process with Path</li>
<li><a href="sysconf.htm">sysconf()</a>--Get system configuration variables</li>
</ul>
<br>
<h3>Example</h3>
<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
for information pertaining to code examples.</p>
<p>The following example opens a directory:</p>
<pre>
#include &lt;sys/types.h&gt;
#include &lt;dirent.h&gt;
#include &lt;sys/stat.h&gt;
#include &lt;sys/types.h&gt;
#include &lt;errno.h&gt;
#include &lt;stdio.h&gt;
void traverse(char *fn, int indent) {
DIR *dir;
struct dirent *entry;
int count;
char path[1025]; /*** EXTRA STORAGE MAY BE NEEDED ***/
struct stat info;
for (count=0; count&lt;indent; count++) printf(" ");
printf("%s\n", fn);
if ((dir = opendir(fn)) == NULL)
perror("opendir() error");
else {
while ((entry = readdir(dir)) != NULL) {
if (entry-&gt;d_name[0] != '.') {
strcpy(path, fn);
strcat(path, "/");
strcat(path, entry-&gt;d_name);
if (stat(path, &amp;info) != 0)
fprintf(stderr, "stat() error on %s: %s\n", path,
strerror(errno));
else if (S_ISDIR(info.st_mode))
traverse(path, indent+1);
}
}
closedir(dir);
}
}
main() {
puts("Directory structure:");
traverse("/etc", 0);
}
</pre>
<p><strong>Output:</strong></p>
<pre>
Directory structure:
/etc
/etc/samples
/etc/samples/IBM
/etc/IBM
</pre>
<br>
<hr>
API introduced: V3R1
<hr>
<center>
<table cellpadding="2" cellspacing="2">
<tr align="center">
<td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href=
"unix.htm">UNIX-Type APIs</a> | <a href="aplist.htm">APIs by category</a></td>
</tr>
</table>
</center>
</body>
</html>
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