I want to write a shell script, which will run fdisk -l and extract a string /dev/sdbn from the output of fdisk -l.
Using extracted word I want to mount it to /mnt.
For Example:
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 * 1 493 3956672 6 FAT16
How do I only extract the string /dev/sdb1?
Try:
fdisk -l | grep -o '^/dev/sdb[0-9]'
The -o option causes grep to print only matching pattern.
Updated
If you want all except /dev/sdaX, you can use:
fdisk -l | grep -o '^/dev/sd[b-z][0-9]'
/dev/sdb1 and /dev/sdc1 ?
sed or awk are faster than the equivalent grep, it is not a general rule. In most cases, grep will be faster than either sed or awk. Even in this very simple case, the awk approach took 0.02968 seconds while the grep took 0.02782. This is the average over 100 runs. Please don't make unsubstantiated claims like that.
Use this command :
fdisk -l | awk '/\/dev\/sdb[0-9]/ {print $1}'
^, for good measure... Upvoted.
Commented
Jul 7, 2014 at 9:35
/dev/sdb1 and /dev/sdc1 ?
fdisk -l | awk '/\/dev\/sd[a-z][0-9]/ {print $1}'
You can use sed...
Since a directory-path contains /, I've chosen to use _ to delimit the sed-command (although one usually use /, any symbol can be used as delimiter).
fdisk -l | sed -n 's_^\(/dev/[^ ]*\) .*$_\1_p'
head -n 1 after the sed - or simply fgrep 'sdb1' or fgrep '/dev/sdb1' before or after the sed... You can also simply change the script and replace /dev/[^ ]* with /dev/sdb1 and keep the rest as before.
Commented
Jul 7, 2014 at 9:30
Try this
for getting /dev/sdb1
fdisk -l | grep -w "/dev/sdb1" | awk '{print $1}'
grep is not required.awk only can match the pattern and print the first word fdisk -l | awk '/\/dev\/sdb1/ {print $1}'
For those who don't have root access, you can use a simple ls:
ls /dev/sd* | grep -o '/dev/sd[a-z][1-9]'
Edit regular expression as you want.
UPDATE: As @StéphaneChazelas mentioned, presence of device files won't confirm existence of the underlying device. It would be safer to query /proc/partitions instead:
awk '$NF ~ /^sd[a-z][0-9]+/ {print "/dev/" $NF}' < /proc/partitions
echo /dev/sd[a-z][1-9], though depending on your system those devices files may exist even though the underlying device doesn't exist. Also awk '$NF ~ /^sd[a-z][0-9]+/ {print "/dev/" $NF}' < /proc/partitions to query what the kernel really knows about partitions on devices using the sd subsystem.
Commented
Oct 11, 2015 at 11:35
/dev, e.g. if you know it'ssdbyou can list/dev/sdb[1-9]*.