1BLKID(8) System Manager's Manual BLKID(8)
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6 blkid - command-line utility to locate/print block device attributes
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9 blkid [ -ghlv ] [ [ -c cachefile ] -w writecachefile ] [ -o format ] [
10 -s tag ] [ -t NAME=value ] [ device ... ]
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13 The blkid program is the command-line interface to working with libu‐
14 uid(3) library. It can determine the type of content (e.g. filesystem,
15 swap) a block device holds, and also attributes (tokens, NAME=value
16 pairs) from the content metadata (e.g. LABEL or UUID fields).
17 blkid has two main forms of operation: either searching for a device
19 with a specific NAME=value pair, or displaying NAME=value pairs for one
20 or more devices.
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23 -c Read from cachefile instead of reading from the default cache
24 file /etc/blkid/blkid.tab. If you want to start with a clean
25 cache (i.e. don't report devices previously scanned but not nec‐
26 essarily available at this time), specify /dev/null.
27 -g Perform a garbage collection pass on the blkid cache.
29 -h Display a usage message and exit.
31 -l Look up one device that matches the search parameter specified
33 using the -t option. If there are multiple devices that match
34 the specified search parameter, then the device with the highest
35 priority is returned, and/or the first device found at a given
36 priority. Device types in order of decreasing priority are
37 Device Mapper, EVMS, LVM, MD, and finally regular block devices.
38 If this option is not specified, blkid will print all of the
39 devices that match the search parameter.
40 -o Display blkid's output using the specified format. The format
42 parameter may be full, (the default), value, (only print the
43 value of any tags printed by blkid) or device (only print the
44 device name).
45 -s Show only the tags for each (specified) device that match tag.
47 It is possible to specify multiple -s options. If no tag is
48 specified, then all tokens are shown for all (specified)
49 devices. In order to just refresh the cache without showing any
50 tokens use -s none with no other options.
51 -t Search for block devices with tokens named NAME that have the
53 value value, and display any devices which are found. Common
54 values for NAME include TYPE, LABEL, and UUID. If there are no
55 devices specified on the command line, all block devices will be
56 searched; otherwise, only search the devices specified by the
57 user.
58 -v Display version number and exit.
60 -w <writecachefile> Write the device cache to writecachefile
62 instead of writing it to the default cache file
63 /etc/blkid/blkid.tab. If you don't want to save the cache to
64 the default file, specify /dev/null. If not specified it will
65 be the same file as that given by the -c option.
66 <device>
68 Display tokens from only the specified device. It is possible
69 to give multiple <device> options on the command line. If none
70 is given, all devices which appear in /proc/partitions are
71 shown, if they are recognized.
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74 If the specified token was found, or if any tags were shown from (spec‐
75 ified) devices 0 is returned. If the specified token was not found, or
76 no (specified) devices could be identified, an exit code of 2 is
77 returned. For usage or other errors, an exit code of 4 is returned.
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80 blkid was written by Andreas Dilger for libblkid.
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83 blkid is part the e2fsprogs package since version 1.26 and is available
84 from http://e2fsprogs.sourceforge.net.
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87 libblkid(3)
88E2fsprogs version 1.40.2 July 2007 BLKID(8)