Extract serial number from hdparm output

Question

I am trying to automate the use of shred and putting the output into log files. Currently I am copying the serial number manually using

hdparm -I /dev/sd? | grep 'Serial\ Number'

I know that there is a way to have grep give me only the number and not the "Serial Number" text before it but I don't know how. Could someone how knows reg expressions help me?

See my answer on Harddisk serial number from terminal? – don_crissti Sep 03 '16 at 01:25 — don_crissti, Sep 03 '16 at 01:25

score 5 · Answer 1 · edited Sep 02 '16 at 15:50

5

Try awk instead of grep:

hdparm -I /dev/sd? | awk '/Serial Number/ { print $3 }'

or specify separator rather than accepting default of whitespace

hdparm -I /dev/sd? | awk -F':' '/Serial Number/ { print $2 }'

edited Sep 02 '16 at 15:50

Stephen Kitt

434,908

answered Sep 02 '16 at 15:49

user4556274

8,995
2
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1

The second form has the disadvantage of leaving all the spaces between the colon and the serial number. – Stephen Kitt Sep 02 '16 at 15:51

score 3 · Answer 2 · answered Sep 02 '16 at 15:57

3

As that xkcd strip mentions perl, let's have a perl solution:

hdparm -I /dev/sd? | perl -nle '/Serial Number:\s+(.+)$/ && print $1'

A perl version of the awk solution in the other answer:

hdparm -I /dev/sd? | perl -anle '/Serial Number:/ && print $F[2]'

answered Sep 02 '16 at 15:57

Henrik supports the community

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score 3 · Answer 3 · edited May 23 '17 at 12:40

3

Try

hdparm -I /dev/sd? | grep -oP 'Serial Number:\s*\K.*'

This uses positive lookbehind to ignore pattern before our required string.. in this case Serial Number:\s*

edited May 23 '17 at 12:40

Community

1

answered Sep 02 '16 at 16:22

Sundeep

12,008

score 1 · Answer 4 · answered Sep 02 '16 at 22:32

sed?

hdparm -I /dev/sd? | sed -n 's/^.*Serial\ Number:  *\(.*\)$/\1/p'

(probably lots of other ways to do this using sed - this is just one way that I like: suppress the default print; match the required portion of the line; replace the entire line with it; then print it out.)

Extract serial number from hdparm output

4 Answers4