Using grep for multiple search patterns

Question

Consider I have the following stream of data:

BODY1
attrib1:  someval11
attrib2:  someval12
attrib3:  someval13

BODY2
attrib1:  someval21
attrib2:  someval22
attrib3:  someval23

BODY3
attrib1:  someval31
attrib2:  someval32
attrib3:  someval33

I want to extract only attrib1 and attrib3 for each BODY, i.e.

attrib1:  someval11
attrib3:  someval13
attrib1:  someval21
attrib3:  someval23
attrib1:  someval31
attrib3:  someval33

I tried

grep 'attrib1\|attrib3', according to this site but that returned nothing. grep attrib1 and grep attrib2 do return data but just for the single pattern specified.

Not that it solves your problem, but it may be easier to follow and faster for grep to find if your regex is `attrib[13]`. Making the common part longer is usually better. — Andy Lester, Nov 28 '12 at 17:17
what if there was no commong pattern between attrib 1 and 3? if they were named something completelty different? — amphibient, Nov 28 '12 at 17:18
in the real example, my attrib1 is called foo and attrib3 is called bar... — amphibient, Nov 28 '12 at 17:19
I don't understand -- does it **have** to be grep? axiom showed how to do it, but why not just use awk? Am I the only one who finds it simpler for this kind of tasks? — loreb, Nov 29 '12 at 21:38
i would assume because searching for a single pattern would most easily be done in `grep` that so would searching for multiple ones as a matter of natural progression. — amphibient, Nov 29 '12 at 23:15
@amphibient If your question was answered, please accept one of the answers. — axiom, Feb 03 '17 at 22:25

axiom · Answer 1 · 2012-11-28T17:23:22.927

29

grep -e 'attrib1' -e 'attrib3' file

From the man page :

-e PATTERN, --regexp=PATTERN
Use PATTERN as the pattern. This can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-). (-e is specified by POSIX.)

Edit : Alternatively , you can save patterns in a file and use the -f option :

aman@aman-VPCEB14EN:~$ cat>patt
attrib1
attrib3

aman@aman-VPCEB14EN:~$ grep -f patt test
attrib1:  someval11
attrib3:  someval13
attrib1:  someval21
attrib3:  someval23
attrib1:  someval31
attrib3:  someval33

edited Nov 28 '12 at 17:23

answered Nov 28 '12 at 17:14

axiom

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grep: illegal option -- e. i am using SunOS – amphibient Nov 28 '12 at 17:17
@foampile You may try and see if `-f` option is of any use. Also note that for your example, `grep 'attrib1\|attrib3'` should also work fine. – axiom Nov 28 '12 at 17:25

score 23 · Answer 2 · edited May 13 '21 at 19:05

23

Very simple command:

 bash> grep  "attrib1\|attrib3" <file.name>
attrib1:  someval11
attrib3:  someval13
attrib1:  someval21
attrib3:  someval23
attrib1:  someval31
attrib3:  someval33

edited May 13 '21 at 19:05

tripleee

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answered Apr 28 '14 at 09:07

SteveScm

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score 19 · Answer 3 · answered Oct 16 '13 at 05:34

19

Also egrep;

egrep "pattern1|pattern2|pattern3" file

answered Oct 16 '13 at 05:34

Mike Makuch

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Or `grep -E "pattern1|pattern2|pattern3" file` – kayochin Sep 10 '20 at 12:06

Sirch · Answer 4 · 2012-11-28T17:25:03.193

1

This works, with GNU grep 2.6.3

grep "attrib[13]"

or

 grep "^[^0-9]*[13]:"

edited Nov 28 '12 at 17:25

answered Nov 28 '12 at 17:14

Sirch

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what if there was no commong pattern between attrib 1 and 3? if they were named something completelty different? – amphibient Nov 28 '12 at 17:18
What are you looking for, a 1 or 3 on the end of the first word of the line and followed by a colon? – Sirch Nov 28 '12 at 17:21
how can I do the same if I had strings with more then one character? something like: very-long-attribute-with-Jon-in-the-middle very-long-attribute-with-Tony-in-the-middle very-long-attribute-with-Richard-in-the-middle so provide something that looks like: "very-long-attribute-with-[Tony|Richard|Jon]-in-the-middle" – Charbel Jun 13 '22 at 10:28

score 0 · Answer 5 · edited Oct 16 '13 at 05:25

0

It depends on the shell you are into. grep -iw 'patter1\|patter2\|pattern3' works on bash shell where as it doesn't work on korn shell. For korn shell we might have to try grep -e pattern1 -e patter2 and so on.

edited Oct 16 '13 at 05:25

Yu Hao

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answered Oct 16 '13 at 05:18

Siva

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Which shell you use has no direct bearing on what parameters the `grep` external command supports. – tripleee Oct 10 '16 at 20:01

Using grep for multiple search patterns

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