hdf5/doc/html/RM_H5F.html
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RM_H5S.html
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	H5Screate
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RM_H5G.html
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	    Corrected descriptions of 'loc_id', 'name', and 'value'.
	    Corrected "Purpose".
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	H5Gset_comment
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	H5Gget_objinfo
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RM_H5F.html
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RM_H5T.html
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<html>
<head><title>
HDF5/H5F API Specification
</title></head>
<body bgcolor="#FFFFFF">
<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="H5.intro.html">Introduction to HDF5</a>&nbsp;<br>
<a href="H5.user.html">HDF5 User Guide</a>&nbsp;<br>
<a href="index.html">Other HDF5 documents and links</a>&nbsp;<br>
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<a href="Glossary.html">Glossary</a><br>
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</td>
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And in this document, the
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;&nbsp;
<br>
<a href="RM_H5.html">H5</a>&nbsp;&nbsp;
<a href="RM_H5A.html">H5A</a>&nbsp;&nbsp;
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</td></tr>
</table>
</center>
<hr>
<center>
<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>
<li><a href="#File-IsHDF5">H5Fis_hdf5</a>
</ul>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<ul>
<li><a href="#File-Flush">H5Fflush</a>
<li><a href="#File-Close">H5Fclose</a>
<li><a href="#File-Mount">H5Fmount</a>
<li><a href="#File-Unmount">H5Funmount</a>
<li><a href="#File-Reopen">H5Freopen</a>
</ul>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<ul>
<li><a href="#File-GetCreatePlist">H5Fget_create_plist</a>
<li><a href="#File-GetAccessPlist">H5Fget_access_plist</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 returns a negative value.
</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 property list value indicates that the library should use
the default values for the appropriate property list. 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 property list 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_id</code>.
Use <code>0</code> for default access properties.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a file identifier if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Flush">H5Fflush</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t </em><code>H5Fflush</code>(<em>hid_t </em><code>object_id</code>,
<em>H5F_scope_t</em> <code>scope</code>
)
<dt><strong>Purpose:</strong>
<dd>Flushes all buffers associated with a file to disk.
<dt><strong>Description:</strong>
<dd><code>H5Fflush</code> causes all buffers associated with a
file to be immediately flushed to disk without removing the
data from the cache.
<p>
<code>object_id</code> can be any object associated with the file,
including the file itself, a dataset, a group, an attribute, or
a named data type.
<p>
<code>scope</code> specifies whether the scope of the flushing
action is global or local. Valid values are
<center>
<table border=0>
<tr><td align=left valign=bottom><code>H5F_SCOPE_GLOBAL</code></td>
<td>&nbsp;&nbsp;&nbsp;&nbsp;</td>
<td align=left valign=bottom>Flushes the entire virtual file.</td></tr>
<tr><td align=left valign=bottom><code>H5F_SCOPE_LOCAL</code></td>
<td></td>
<td align=left valign=bottom>Flushes only the specified file.</td></tr>
</table>
</center>
<dt><strong>Parameters:</strong>
<dl>
<dt><em>const char *</em><code>object_id</code>
<dd>Identifier of object used to identify the file.
<dt><em>H5F_scope_t</em> <code>scope</code>
<dd>Specifies the scope of the flushing action.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</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 a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-GetCreatePlist">H5Fget_create_plist</a>
<dt><strong>Signature:</strong>
<dd><em>hid_t </em><code>H5Fget_create_plist</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_plist</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 returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-GetAccessPlist">H5Fget_access_plist</a>
<dt><strong>Signature:</strong>
<dd><em>hid_t </em><code>H5Fget_access_plist</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_plist</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 returns a negative value.
</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 a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Mount">H5Fmount</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Fmount</code>(<em>hid_t</em> <code>loc_id</code>,
<em>const char *</em><code>name</code>,
<em>hid_t</em> <code>child_id</code>,
<em>hid_t</em> <code>plist_id</code>
)
<dt><strong>Purpose:</strong>
<dd>Mounts a file.
<dt><strong>Description:</strong>
<dd><code>H5Fmount</code> mounts the file specified by
<code>child_id</code> onto the group specified by
<code>loc_id</code> and <code>name</code> using
the mount properties <code>plist_id</code>.
<p>
Note that <code>loc_id</code> identifies a file or group.
<code>name</code> then specifies a group relative to <code>loc_id</code>.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>hid_t</em> <code>loc_id</code>
<dd>The identifier for of file or group in
which <code>name</code> is defined.
<dt><em>const char *</em><code>name</code>
<dd>The name of the group onto which the
file specified by <code>child_id</code>
is to be mounted.
<dt><em>hid_t</em> <code>child_id</code>
<dd>The identifier of the file to be mounted.
<dt><em>hid_t</em> <code>plist_id</code>
<dd>The identifier of the property list to be used.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Unmount">H5Funmount</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Funmount</code>(<em>hid_t</em> <code>loc_id</code>,
<em>const char *</em><code>name</code>
)
<dt><strong>Purpose:</strong>
<dd>Unmounts a file.
<dt><strong>Description:</strong>
<dd>Given a mount point, <code>H5Funmount</code>
dissassociates the mount point's file
from the file mounted there. This function
does not close either file.
<p>
The mount point can either be the group in the
parent or the root group of the mounted file
(both groups have the same name). If the mount
point was opened before the mount then it is the
group in the parent; if it was opened after the
mount then it is the root group of the child.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>hid_t</em> <code>loc_id</code>
<dd>The file or group identifier for the location at which
the specified file is to be unmounted.
<dt><em>const char *</em><code>name</code>
<dd>The name of the file to be unmounted.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="File-Reopen">H5Freopen</a>
<dt><strong>Signature:</strong>
<dd><em>hid__t </em><code>H5Freopen</code>(<em>hid_t</em> <code>file_id</code>
)
<dt><strong>Purpose:</strong>
<dd>Reopens an HDF5 file.
<dt><strong>Description:</strong>
<dd><code>H5Freopen</code> reopens an HDF5 file. The new
file identifier which is returned points to the same file
as the specified file idetifier, <code>file_id</code>.
Both identifiers share caches and other information.
The only difference between the identifiers is that the
new identifier is not mounted anywhere and no files are
mounted on it.
<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 a new file identifier if successful;
otherwise returns a negative value.
</dl>
<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="H5.intro.html">Introduction to HDF5</a>&nbsp;<br>
<a href="H5.user.html">HDF5 User Guide</a>&nbsp;<br>
<a href="index.html">Other HDF5 documents and links</a>&nbsp;<br>
<!--
<a href="Glossary.html">Glossary</a><br>
-->
</td>
<td valign=top align=right>
And in this document, the
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;&nbsp;
<br>
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<a href="Tools.html">Tools</a>&nbsp;&nbsp;
</td></tr>
</table>
</center>
<hr>
<address>
<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a>
<br>
Last modified: 30 October 1998
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