hdf5/doc/html/RM_H5F.html
Frank Baker c8e75d27b0 [svn-r503] HDF5 Reference Manual
Updated for Alpha2.
1998-07-14 23:51:50 -05:00

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<head><title>
HDF5/H5F Draft API Specification
</title></head>
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<center>
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;
<a href="RM_H5.html">H5</a>&nbsp;&nbsp;
<a href="RM_H5A.html">H5A</a>&nbsp;&nbsp;
<a href="RM_H5D.html">H5D</a>&nbsp;&nbsp;
<a href="RM_H5E.html">H5E</a>&nbsp;&nbsp;
H5F&nbsp;&nbsp;
<a href="RM_H5G.html">H5G</a>&nbsp;&nbsp;
<a href="RM_H5P.html">H5P</a>&nbsp;&nbsp;
<a href="RM_H5S.html">H5S</a>&nbsp;&nbsp;
<a href="RM_H5T.html">H5T</a>&nbsp;&nbsp;
<a href="RM_H5Z.html">H5Z</a>&nbsp;&nbsp;
<a href="Glossary.html">Glossary</a>
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<h1>H5F: File Interface</h1>
</center>
<h2>File API Functions</h2>
These functions are designed to provide file-level access to HDF5 files.
Further manipulation of objects inside a file is performed through one of APIs
documented below.
<table border=0>
<tr><td valign=top>
<ul>
<li><a href="#File-Open">H5Fopen</a>
<li><a href="#File-Create">H5Fcreate</a>
</ul>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<ul>
<li><a href="#File-IsHDF5">H5Fis_hdf5</a>
<li><a href="#File-Close">H5Fclose</a>
</ul>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<ul>
<li><a href="#File-GetCreateTemplate">H5Fget_create_template</a>
<li><a href="#File-GetAccessTemplate">H5Fget_access_template</a>
</ul>
</td></tr>
</table>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Open">H5Fopen</a>
<dt><strong>Signature:</strong>
<dd><em>hid_t </em><code>H5Fopen</code>(<em>const char *</em><code>name</code>,
<em>unsigned</em> <code>flags</code>,
<em>hid_t</em> <code>access_id</code>
)
<dt><strong>Purpose:</strong>
<dd>Opens an existing file.
<dt><strong>Description:</strong>
<dd><code>H5Fopen</code> opens an existing file and is the primary
function for accessing existing HDF5 files.
<p>
The parameter <code>access_id</code> is a file access property
list identifier or <code>H5P_DEFAULT</code> for the default I/O access
parameters.
<p>
The <code>flags</code> argument determines whether writing
to an existing file will be allowed or not.
The file is opened with read and write permission if
<code>flags</code> is set to <code>H5F_ACC_RDWR</code>.
All flags may be combined with the bit-wise OR operator (`|')
to change the behavior of the file open call.
The more complex behaviors of a file's access are controlled
through the file-access property list.
<p>
Files which are opened more than once return a unique identifier
for each <code>H5Fopen()</code> call and can be accessed
through all file identifiers.
<p>
The return value is a file identifier for the open file and it
should be closed by calling <code>H5Fclose()</code> when it is
no longer needed.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>const char *</em><code>name</code>
<dd>Name of the file to access.
<dt><em>unsigned</em> <code>flags</code>
<dd>File access flags. See the <code>H5Fcreate</code>
parameters list for a list of possible values.
<dt><em>hid_t</em> <code>access_id</code>
<dd>Identifier for the file access properties list.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a file identifier if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Create">H5Fcreate</a>
<dt><strong>Signature:</strong>
<dd><em>hid_t </em><code>H5Fcreate</code>(<em>const char *</em><code>name</code>,
<em>unsigned</em> <code>flags</code>,
<em>hid_t</em> <code>create_id</code>,
<em>hid_t</em> <code>access_id</code>
)
<dt><strong>Purpose:</strong>
<dd>Creates HDF5 files.
<dt><strong>Description:</strong>
<dd><code>H5Fcreate</code> is the primary function for creating
HDF5 files .
<p>
The <code>flags</code> parameter determines whether an
existing file will be overwritten. All newly created files
are opened for both reading and writing. All flags may be
combined with the bit-wise OR operator (`|') to change
the behavior of the <code>H5Fcreate</code> call.
<p>
The more complex behaviors of file creation and access
are controlled through the file-creation and file-access
property lists. The value of <code>H5P_DEFAULT</code> for
a template value indicates that the library should use
the default values for the appropriate template. Also see
<code>H5Fpublic.h</code> for the list of supported flags.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>const char *</em><code>name</code>
<dd>Name of the file to access.
<dt><em>uintn</em> <code>flags</code>
<dd>File access flags. Possible values include:
<ul><dl>
<dt>H5F_ACC_RDWR
<dd>Allow read and write access to file.
<dt>H5F_ACC_RDONLY
<dd>Allow read-only access to file.
<dt>H5F_ACC_TRUNC
<dd>Truncate file, if it already exists,
erasing all data previously stored in the file.
<dt>H5F_ACC_EXCL
<dd>Fail if file already exists.
<dt>H5F_ACC_DEBUG
<dd>Print debug information.
<dt>H5P_DEFAULT
<dd>Apply default file access and creation properties.
</dl></ul>
<dt><em>hid_t</em> <code>create_id</code>
<dd>File creation template identifier, used when modifying
default file meta-data.
<dt><em>hid_t</em> <code>access_id</code>
<dd>File access property list identifier.
If parallel file access is desired, this is a collective
call according to the communicator stored in the
<code>access_template</code>.
Use <code>0</code> for default access template.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a file identifier if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-IsHDF5">H5Fis_hdf5</a>
<dt><strong>Signature:</strong>
<dd><em>hbool_t </em><code>H5Fis_hdf5</code>(<em>const char *</em><code>name</code>
)
<dt><strong>Purpose:</strong>
<dd>Determines whether a file is in the HDF5 format.
<dt><strong>Description:</strong>
<dd><code>H5Fis_hdf5</code> determines whether a file is in
the HDF5 format.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>const char *</em><code>name</code>
<dd>File name to check format.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns <code>TRUE</code> or <code>FALSE</code> if successful.
Otherwise returns FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-GetCreateTemplate">H5Fget_create_template</a>
<dt><strong>Signature:</strong>
<dd><em>hid_t </em><code>H5Fget_create_template</code>(<em>hid_t</em> <code>file_id</code>
)
<dt><strong>Purpose:</strong>
<dd>Returns a file creation property list identifier.
<dt><strong>Description:</strong>
<dd><code>H5Fget_create_template</code> returns a file creation
property list identifier identifying the creation properties
used to create this file. This function is useful for
duplicating properties when creating another file.
<p>
See "File Creation Properties" in
<a href="RM_H5P.html">H5P: Property List Interface</a>
in this reference manual and
"File Creation Properties"
in <a href="Files.html"><cite>Files</cite></a> in the
<cite>HDF5 User's Guide</cite> for
additional information and related functions.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>hid_t</em> <code>file_id</code>
<dd>Identifier of the file to get creation property list of
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a file creation property list identifier if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-GetAccessTemplate">H5Fget_access_template</a>
<dt><strong>Signature:</strong>
<dd><em>hid_t </em><code>H5Fget_access_template</code>(<em>hid_t</em> <code>file_id</code>)
<dt><strong>Purpose:</strong>
<dd>Returns a file access property list identifier.
<dt><strong>Description:</strong>
<dd><code>H5Fget_access_template</code> returns the
file access property list identifier of the specified file.
<p>
See "File Access Properties" in
<a href="RM_H5P.html">H5P: Property List Interface</a>
in this reference manual and
"File Access Property Lists"
in <a href="Files.html"><cite>Files</cite></a> in the
<cite>HDF5 User's Guide</cite> for
additional information and related functions.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>hid_t</em> <code>file_id</code>
<dd>Identifier of file to get access property list of
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a file access property list identifier if successful;
otherwise FAIL (-1).
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Close">H5Fclose</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t </em><code>H5Fclose</code>(<em>hid_t</em> <code>file_id</code>
)
<dt><strong>Purpose:</strong>
<dd>Terminates access to an HDF5 file.
<dt><strong>Description:</strong>
<dd><code>H5Fclose</code> terminates access to an HDF5 file.
If this is the last file identifier open for a file
and if access identifiers are still in use,
this function will fail.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>hid_t</em> <code>file_id</code>
<dd>Identifier of a file to terminate access to.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns SUCCEED (0) if successful;
otherwise FAIL (-1).
</dl>
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Last modified: 14 July 1998
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