lib/blkid/libblkid.3.in - platform/external/e2fsprogs - Git at Google

 .\" Copyright 2001 Andreas Dilger (adilger@turbolinux.com)
 .\"
 .\" This man page was created for libblkid.so.1.0 from e2fsprogs-1.24.
 .\"
 .\" This file may be copied under the terms of the GNU Public License.
 .\"
 .\" Created  Wed Sep 14 12:02:12 2001, Andreas Dilger
 .TH LIBBLKID 3 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
 .SH NAME
 libblkid \- block device identification library
 .SH SYNOPSIS
 .B #include <blkid/blkid.h>
 .sp
 .B cc
 .I file.c
 .B \-lblkid
 .SH DESCRIPTION
 The
 .B libblkid
 library is used to identify block devices (disks) as to their content (e.g.
 filesystem type) as well as extracting additional information such as
 filesystem labels/volume names, unique identifiers/serial numbers, etc.
 A common use is to allow use of LABEL= and UUID= tags instead of hard-coding
 specific block device names into configuration files.
 .P
 Block device information is normally kept in a cache file
 .I /etc/blkid.tab
 and is verified to still be valid before being returned to the user
 (if the user has read permission on the raw block device, otherwise not).
 The cache file also allows unprivileged users (normally anyone other
 than root, or those not in the "disk" group) to locate devices by label/id.
 The standard location of the cache file can be overridden by the
 environment variable BLKID_FILE.
 .P
 In situations where one is getting information about a single known device,
 it does not impact performance whether the cache is used or not (unless you
 are not able to read the block device directly).  If you are dealing with
 multiple devices, use of the cache is highly recommended (even if empty) as
 devices will be scanned at most one time and the on-disk cache will be
 updated if possible.  There is rarely a reason not to use the cache.
 .P
 In some cases (modular kernels), block devices are not even visible until
 after they are accessed the first time, so it is critical that there is
 some way to locate these devices without enumerating only visible devices,
 so the use of the cache file is
 .B required
 in this situation.
 .SH AUTHOR
 .B libblkid
 was written by Andreas Dilger for the ext2 filesystem utilties, with input
 from Ted Ts'o.  The library was subsequently heavily modified by Ted Ts'o.
 .SH FILES
 .TP
 .I /etc/blkid.tab
 Caches data extracted from each recognized block device.
 .SH AVAILABILITY
 .B libblkid
 is part of the e2fsprogs package since version 1.33 and is available from
 http://e2fsprogs.sourceforge.net.
 .SH COPYING
 .B libblkid
 is available under the terms of the GNU Library General Public License (LGPL),
 version 2 (or at your discretion any later version).  A copy of the LGPL
 should be included with this library in the file COPYING.  If not, write to
 .RS
 Free Software Foundation, Inc.
 .br
 51 Franklin St
 .br
 Fifth Floor
 .br
 Boston, MA  02110-1301  USA
 .RE
 .PP
 or visit
 .UR http://www.gnu.org/licenses/licenses.html#LGPL
 http://www.gnu.org/licenses/licenses.html#LGPL
 .UE
 .SH "SEE ALSO"
 .BR blkid (8)
	.\" Copyright 2001 Andreas Dilger (adilger@turbolinux.com)
	.\"
	.\" This man page was created for libblkid.so.1.0 from e2fsprogs-1.24.
	.\"
	.\" This file may be copied under the terms of the GNU Public License.
	.\"
	.\" Created Wed Sep 14 12:02:12 2001, Andreas Dilger
	.TH LIBBLKID 3 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
	.SH NAME
	libblkid \- block device identification library
	.SH SYNOPSIS
	.B #include <blkid/blkid.h>
	.sp
	.B cc
	.I file.c
	.B \-lblkid
	.SH DESCRIPTION
	The
	.B libblkid
	library is used to identify block devices (disks) as to their content (e.g.
	filesystem type) as well as extracting additional information such as
	filesystem labels/volume names, unique identifiers/serial numbers, etc.
	A common use is to allow use of LABEL= and UUID= tags instead of hard-coding
	specific block device names into configuration files.
	.P
	Block device information is normally kept in a cache file
	.I /etc/blkid.tab
	and is verified to still be valid before being returned to the user
	(if the user has read permission on the raw block device, otherwise not).
	The cache file also allows unprivileged users (normally anyone other
	than root, or those not in the "disk" group) to locate devices by label/id.
	The standard location of the cache file can be overridden by the
	environment variable BLKID_FILE.
	.P
	In situations where one is getting information about a single known device,
	it does not impact performance whether the cache is used or not (unless you
	are not able to read the block device directly). If you are dealing with
	multiple devices, use of the cache is highly recommended (even if empty) as
	devices will be scanned at most one time and the on-disk cache will be
	updated if possible. There is rarely a reason not to use the cache.
	.P
	In some cases (modular kernels), block devices are not even visible until
	after they are accessed the first time, so it is critical that there is
	some way to locate these devices without enumerating only visible devices,
	so the use of the cache file is
	.B required
	in this situation.
	.SH AUTHOR
	.B libblkid
	was written by Andreas Dilger for the ext2 filesystem utilties, with input
	from Ted Ts'o. The library was subsequently heavily modified by Ted Ts'o.
	.SH FILES
	.TP
	.I /etc/blkid.tab
	Caches data extracted from each recognized block device.
	.SH AVAILABILITY
	.B libblkid
	is part of the e2fsprogs package since version 1.33 and is available from
	http://e2fsprogs.sourceforge.net.
	.SH COPYING
	.B libblkid
	is available under the terms of the GNU Library General Public License (LGPL),
	version 2 (or at your discretion any later version). A copy of the LGPL
	should be included with this library in the file COPYING. If not, write to
	.RS
	Free Software Foundation, Inc.
	.br
	51 Franklin St
	.br
	Fifth Floor
	.br
	Boston, MA 02110-1301 USA
	.RE
	.PP
	or visit
	.UR http://www.gnu.org/licenses/licenses.html#LGPL
	http://www.gnu.org/licenses/licenses.html#LGPL
	.UE
	.SH "SEE ALSO"
	.BR blkid (8)