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HDF5/H5 Draft API Specification
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<h1>H5: General Library Functions</h1>
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These functions serve general-purpose needs of the HDF5 library
and it users.
<table border=0>
<tr><td valign=top>
<ul>
<li><a href="#Library-Open">H5open</a>
<li><a href="#Library-Close">H5close</a>
</ul>
</td><td> </td><td valign=top>
<ul>
<li><a href="#Library-Version">H5get_libversion</a>
<li><a href="#Library-VersCheck">H5check_version</a>
</ul>
</td><td> </td><td valign=top>
<ul>
<li><a href="#Library-DontAtExit">H5dont_atexit</a>
</ul>
</td></tr>
</table>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Library-Open">H5open</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5open</code>(<em>void</em>)
<dt><strong>Purpose:</strong>
<dd>Flushes all data to disk, closes file identifiers, and cleans up memory.
<dt><strong>Description:</strong>
<dd><code>H5open</code> initialize the library. This function is
normally called automatically, but if you find that an
HDF5 library function is failing inexplicably, try calling
this function first.
<dt><strong>Parameters:</strong>
<dl>
<dt>None.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns SUCCEED (0) if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Library-Close">H5close</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5close</code>(<em>void</em>)
<dt><strong>Purpose:</strong>
<dd>Flushes all data to disk, closes file identifiers, and cleans up memory.
<dt><strong>Description:</strong>
<dd><code>H5close</code> flushes all data to disk,
closes all file identifiers, and cleans up all memory used by
the library. This function is generall called when the
application calls <code>exit</code>, but may be called earlier
in event of an emergency shutdown or out of desire to free all
resources used by the HDF5 library.
<dt><strong>Parameters:</strong>
<dl>
<dt>None.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns SUCCEED (0) if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Library-DontAtExit">H5dont_atexit</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5dont_atexit</code>(<em>void</em>)
<dt><strong>Purpose:</strong>
<dd>Instructs library not to install <code>atexit</code> cleanup routine.
<dt><strong>Description:</strong>
<dd><code>H5dont_atexit</code> indicates to the library that an
<code>atexit()</code> cleanup routine should not be installed.
The major purpose for this is in situations where the
library is dynamically linked into an application and is
un-linked from the application before <code>exit()</code> gets
called. In those situations, a routine installed with
<code>atexit()</code> would jump to a routine which was
no longer in memory, causing errors.
<p>
In order to be effective, this routine <em>must</em> be called
before any other HDF function calls, and must be called each
time the library is loaded/linked into the application
(the first time and after it's been un-loaded).
<dt><strong>Parameters:</strong>
<dl>
<dt>None.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns SUCCEED (0) if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Library-Version">H5get_libversion</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5get_libversion</code>(<em>unsigned *</em><code>majnum</code>,
<em>unsigned *</em><code>minnum</code>,
<em>unsigned *</em><code>relnum</code>
)
<dt><strong>Purpose:</strong>
<dd>Returns the HDF library release number.
<dt><strong>Description:</strong>
<dd><code>H5get_libversion</code> retrieves the major, minor, and release
numbers of the version of the HDF library which is linked to
the application.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>unsigned *</em><code>majnum</code>
<dd>The major version of the library.
<dt><em>unsigned *</em><code>minnum</code>
<dd>The minor version of the library.
<dt><em>unsigned *</em><code>relnum</code>
<dd>The release number of the library.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns SUCCEED (0) if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Library-VersCheck">H5check_version</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5check_version</code>(<em>unsigned</em> <code>majnum</code>,
<em>unsigned</em> <code>minnum</code>,
<em>unsigned</em> <code>relnum</code>
)
<dt><strong>Purpose:</strong>
<dd>
<dt><strong>Description:</strong>
<dd><code>H5check_version</code> verifies that the arguments match the
version numbers compiled into the library. This function is intended
to be called from user to verify that the versions of header files
compiled into the application match the version of the HDF5 library.
<p>
Due to the risks of data corruption or segmentation faults,
<code>H5check_version</code> causes the application to abort if the
version numbers do not match.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>unsigned *</em><code>majnum</code>
<dd>The major version of the library.
<dt><em>unsigned *</em><code>minnum</code>
<dd>The minor version of the library.
<dt><em>unsigned *</em><code>relnum</code>
<dd>The release number of the library.
<dt><em>unsigned *</em><code>patnum</code>
<dd>The patch number of the library.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns SUCCEED (0) if successful.
Upon failure, this function causes the application to abort.
</dl>
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Last modified: 2 September 1998
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