ibm-information-center/dist/eclipse/plugins/i5OS.ic.apis_5.4.0.1/readlinku.htm

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<title>QlgReadlink()--Read Value of Symbolic Link (using NLS-enabled path
name)</title>
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<h2>QlgReadlink()--Read Value of Symbolic Link (using NLS-enabled path
name)</h2>
<div class="box" style="width: 65%;">
<br>
&nbsp;&nbsp;Syntax<br>
<pre>
#include &lt;unistd.h&gt;
int QlgReadlink(Qlg_Path_Name_T <em>*path</em>, Qlg_Path_Name_T <em>*buf</em>,
size_t <em>bufsiz</em>);
</pre>
&nbsp;&nbsp;Service Program Name: QP0LLIB1<br>
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<br>
&nbsp;&nbsp;Default Public Authority: *USE<br>
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<br>
&nbsp;&nbsp;Threadsafe: Conditional; see Usage Notes for <a href="readlink.htm">
readlink()</a>.<br>
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</div>
<p>The <strong>QlgReadlink()</strong> function, like the <strong>
readlink()</strong> function, places the contents of the symbolic link <em>
path</em> in the buffer <em>buf</em>. The difference is that the <strong>
QlgReadlink()</strong> function uses pointers to Qlg_Path_Name_T structures,
while <strong>readlink()</strong> uses pointers to character strings.</p>
<p>Limited information on the <em>path</em> parameter, the <em>buf</em>
parameter, and the <em>size</em> parameter is provided here. For more
information on these parameters and for a discussion on authorities required,
return values, and related information, see <a href="readlink.htm">
readlink()</a>--Read Value of Symbolic Link.</p>
<br>
<h3>Parameters</h3>
<dl>
<dt><strong><em>path</em></strong></dt>
<dd>(Input) A pointer to a Qlg_Path_Name_T structure that contains a path name
or a pointer to a path name of the symbolic link. For more information on the
Qlg_Path_Name_T structure, see <a href="../apiref/pns.htm">Path name format</a>.<br>
<br>
</dd>
<dt><strong><em>buf</em></strong></dt>
<dd>(Output) A pointer to the area in which the contents of the link should be
stored. For more information on the Qlg_Path_Name_T structure, see <a href=
"../apiref/pns.htm">Path name format</a>.<br>
<br>
</dd>
<dt><strong><em>bufsiz</em></strong></dt>
<dd>(Input) The size of <em>buf</em> in bytes.</dd>
</dl>
<br>
<h3>Related Information</h3>
<ul>
<li><a href="readlink.htm">readlink()</a>--Read Value of Symbolic Link
</li>
<li><a href="lstatu.htm">QlgLstat()</a>--Get File or Link Information (using
NLS-enabled path name)
</li>
<li><a href="statu.htm">QlgStat()</a>--Get File Information (using NLS-enabled
path name)
</li>
<li><a href="symlinku.htm">QlgSymlink()</a>--Make Symbolic Link (using
NLS-enabled path name)
</li>
<li><a href="qp0lunlk.htm">Qp0lUnlink()</a>--Remove Link to File</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 uses <strong>QlgReadlink()</strong>:</p>
<pre>
#include &lt;unistd.h&gt;
#include &lt;sys/types.h&gt;
#include &lt;sys/stat.h&gt;
#include &lt;fcntl.h&gt;
#include &lt;stdio.h&gt;
#include &lt;Qp0lstdi.h&gt;
main() {
int file_descriptor;
#define mypath_fn "readlink.file"
#define mypath_sl "readlink.symlink"
const char US_const[3]= "US";
const char Language_const[4]="ENU";
typedef struct pnstruct
{
Qlg_Path_Name_T qlg_struct;
char pn[100]; /* This array size must be &gt;= the length */
/* of the path name or this must be a */
/* pointer to the path name. */
};
struct pnstruct path_fn;
struct pnstruct path_sl;
struct pnstruct path_buf;
/***************************************************************/
/* Initialize Qlg_Path_Name_T parameters */
/***************************************************************/
memset((void*)path name_fn, 0x00, sizeof(struct pnstruct));
path_fn.qlg_struct.CCSID = 37;
memcpy(path_fn.qlg_struct.Country_ID,US_const,2);
memcpy(path_fn.qlg_struct.Language_ID,Language_const,3);
path_fn.qlg_struct.Path_Type = QLG_CHAR_SINGLE;
path_fn.qlg_struct.Path_Length = sizeof(mypath_fn)-1;
path_fn.qlg_struct.Path_Name_Delimiter[0] = '/';
memcpy(path_fn.pn,mypath_fn,sizeof(mypath_fn)-1);
memset((void*)path name_sl, 0x00, sizeof(struct pnstruct));
path_sl.qlg_struct.CCSID = 37;
memcpy(path_sl.qlg_struct.Country_ID,US_const,2);
memcpy(path_sl.qlg_struct.Language_ID,Language_const,3);
path_sl.qlg_struct.Path_Type = QLG_CHAR_SINGLE;
path_sl.qlg_struct.Path_Length = sizeof(mypath_sl)-1;
path_sl.qlg_struct.Path_Name_Delimiter[0] = '/';
memcpy(path_sl.pn,mypath_sl,sizeof(mypath_sl)-1);
if ((file_descriptor = QlgCreat((Qlg_Path_Name_T *)path name_fn, S_IWUSR)) &lt; 0)
perror("QlgCreat() error");
else {
close(file_descriptor);
if (QlgSymlink((Qlg_Path_Name_T *)path name_fn,
(Qlg_Path_Name_T *)path name_sl) != 0)
perror("QlgSymlink() error");
else {
if (QlgReadlink((Qlg_Path_Name_T *)path name_sl,
(Qlg_Path_Name_T *)path name_buf,
sizeof(path_buf)) &lt; 0)
perror("QlgReadlink() error");
else printf("QlgReadlink() returned '%s' for '%s'\n",
path name_buf.pn,
path name_sl.pn);
QlgUnlink((Qlg_Path_Name_T *)path name_sl);
}
QlgUnlink((Qlg_Path_Name_T *)path name_fn);
}
}
</pre>
<p><strong>Output:</strong></p>
<pre>
QlgReadlink() returned 'readlink.file' for 'readlink.symlink'
</pre>
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API introduced: V5R1
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