-This program is normally called from a udev rule, to provide udev with the
-filesystem type of a volume and the label and uuid to name a device node.
-vol_id opens the blockdevice node specified at the commandline. The following
-commandline switches are supported to specify what vol_id should print:
- --export export key/value pairs
- --type filesystem type
- --label filesystem label
- --label-raw raw label
- --uuid filesystem uuid
- --skip-raid don't probe for raid
- --probe-all find possibly conflicting signatures
- --help
+vol_id will only return with a non-zero exit code if the string asked for,
+is not empty. All trailing whitespace will be removed, spaces replaced by
+underscore and slashes ignored.
+Unmangled values are available in the --export mode as hex-encoded strings
+in *_ENC= keys.
+
+ $ extras/volume_id/vol_id --export /dev/sda6
+ ID_FS_USAGE=filesystem
+ ID_FS_TYPE=ext3
+ ID_FS_VERSION=1.0
+ ID_FS_UUID=3e999973-00c9-4917-9442-b7633bd95b9e
+ ID_FS_UUID_ENC=3e999973-00c9-4917-9442-b7633bd95b9e
+ ID_FS_LABEL=devel
+ ID_FS_LABEL_ENC=devel
+
+ $ extras/volume_id/vol_id --label /dev/sda6
+ devel
+
+ $ extras/volume_id/vol_id --type /dev/sda6
+ ext3