Provided by: libblkid1_1.38-2ubuntu2_i386 bug

NAME

       blkid - command-line utility to locate/print block device attributes

SYNOPSIS

       blkid  [  -hlv ] [ [ -c cachefile ] -w writecachefile ] [ -o format ] [
       -s tag ] [ -t NAME=value ] [ device ...  ]

DESCRIPTION

       The blkid  program  is  the  command-line  interface  to  working  with
       libuuid(3)  library.   It  can  determine  the  type  of  content (e.g.
       filesystem, swap) a block device holds, and  also  attributes  (tokens,
       NAME=value  pairs)  from  the  content  metadata  (e.g.  LABEL  or UUID
       fields).

       blkid has two main forms of operation: either searching  for  a  device
       with a specific NAME=value pair, or displaying NAME=value pairs for one
       or more devices.

OPTIONS

       -c     Read from cachefile instead of reading from  the  default  cache
              file  /etc/blkid.tab.   If  you want to start with a clean cache
              (i.e.  don’t  report  devices   previously   scanned   but   not
              necessarily available at this time), specify /dev/null.

       -h     Display a usage message and exit.

       -l     Look  up  the device that matches the search parameter specified
              using the -t option, assuming that there is  only  one  matching
              the  search  parameter.   For  a  system  with a large number of
              disks, this will be more  efficient  by  avoiding  the  need  to
              revalidate  devices unless absolutely necessary.  If this option
              is not specified, blkid will  use  a  less  efficient  approach,
              which  allows  blkid  to print all of the devices that match the
              search parameter.

              This option is best used for tag searches such as LABEL=data_vol
              or UUID=e280469a-d06f-4c0b-b068-44f3b576029e.  If you want blkid
              to print all of the ext3 filesystems using  a  search  parameter
              such as TYPE=ext3, then this option should not be used.

       -o     Display  blkid’s  output using the specified format.  The format
              parameter may be full, (the default),  value,  (only  print  the
              value  of  any  tags printed by blkid) or device (only print the
              device name).

       -s     Show only the tags for each (specified) device that  match  tag.
              It  is  possible  to  specify multiple -s options.  If no tag is
              specified,  then  all  tokens  are  shown  for  all  (specified)
              devices.  In order to just refresh the cache without showing any
              tokens use -s none with no other options.

       -t     Search for block devices with tokens named NAME  that  have  the
              value  value,  and  display any devices which are found.  Common
              values for NAME include TYPE, LABEL, and UUID.  If there are  no
              devices specified on the command line, all block devices will be
              searched; otherwise, only search the devices  specified  by  the
              user.

       -v     Display version number and exit.

       -w     <writecachefile>   Write  the  device  cache  to  writecachefile
              instead of writing it to the default cache file  /etc/blkid.tab.
              If you don’t want to save the cache to the default file, specify
              /dev/null.  If not specified it will be the same  file  as  that
              given by the -c option.

       <device>
              Display  tokens  from only the specified device.  It is possible
              to give multiple <device> options on the command line.  If  none
              is  given,  all  devices  which  appear  in /proc/partitions are
              shown, if they are recognized.

RETURN CODE

       If the specified token was found,  or  if  any  tags  were  shown  from
       (specified)  devices  0  is  returned.   If the specified token was not
       found, or no (specified) devices could be identified, an exit code of 2
       is returned.  For usage or other errors, an exit code of 4 is returned.

AUTHOR

       blkid was written by Andreas Dilger for libblkid.

AVAILABILITY

       blkid is part the e2fsprogs package since version 1.26 and is available
       from http://e2fsprogs.sourceforge.net.

SEE ALSO

       libblkid(3)