How can I use grep to get the line number without the output?

Question

Possible Duplicate:
Use grep to report back only line numbers

I only want to see the line number. I don't need to see the remaining output.

http://stackoverflow.com/questions/6958841/use-grep-to-report-back-only-line-numbers — maialithar, Dec 24 '12 at 07:41

score 5 · Accepted Answer · answered Dec 24 '12 at 07:43

5

Pipe your grep -n output, which normally looks something like:

11: stuff that matched
43: more stuff that matched

through sed to strip out the matching parts:

grep -n pattern file | sed -e 's/:.*//g'

11
43

answered Dec 24 '12 at 07:43

Amir T

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Wonderful,thank you,though I have anther question:how can i get the first match result? – choujayyl Dec 24 '12 at 09:59
And can you introduce the string " :.* ",what are they representative? – choujayyl Dec 24 '12 at 10:14
its a substitution of the colon and anything that appears after it with the empty string "//" there is an explanation of the regular expression here where you can also play around with it: http://regex101.com/r/nS9jM7 – Amir T Dec 24 '12 at 21:53
Ok,but you don't anwser me the anther question:how can i get the first match result? – choujayyl Dec 25 '12 at 00:57
If you want to get the first line (of anything) you can pipe it to "head -n1" so "grep -n pattern file | sed -e 's/:.*//g' | head -n1 – Amir T Dec 26 '12 at 22:38

L0j1k · Answer 2 · 2012-12-24T09:14:16.090

0

grep -n or --line-number option will do this for you. You can find this information in the grep help file, which you can find by using grep --help or grep --help | less to read it more carefully. Also consider using the manual page: man grep

edited Dec 24 '12 at 09:14

answered Dec 24 '12 at 07:40

L0j1k

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grep -h is for suppress the prefixing filename on output,but I don't want the content , not the filename. – choujayyl Dec 24 '12 at 08:48
Sorry, you're totally right. – L0j1k Dec 24 '12 at 09:14

squiguy · Answer 3 · 2012-12-24T09:36:56.370

0

You could use awk too.

grep -n word file | awk -F: '{ print $1 }'

As @Barmar pointed out you could just use an awk one-liner as such:

awk '/regex/ { print NR }' file

Since you don't have awk you could also use cut:

grep -n word file | cut -d: -f1

edited Dec 24 '12 at 09:36

answered Dec 24 '12 at 07:45

squiguy

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for fun, just a grep pipeline too: grep -n alert test.html | egrep -o '^[0-9]+:' | egrep -o '^[0-9]+' #:-) – Amir T Dec 24 '12 at 07:49
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If you're going to use `awk`, why bother with `grep`, since `awk` can do regex matching itself and it has a variable with the line number? – Barmar Dec 24 '12 at 07:53
@Barmar There is always more than one way to do something. I just quickly wrote that up. – squiguy Dec 24 '12 at 07:55
Unfortunatly,my linux is not have awk.. – choujayyl Dec 24 '12 at 08:54
@choujayyl What Linux do you have that does not have awk? – squiguy Dec 24 '12 at 08:57
@squiguy awk: cannot open /home/user/myexe/external_symbols.awk (No such file or directory)... – choujayyl Dec 24 '12 at 08:59
@choujayyl Try using `/usr/bin/awk` or `/bin/awk`. – squiguy Dec 24 '12 at 09:01
@squiguy how can i change the path .. – choujayyl Dec 24 '12 at 10:00
@choujayyl You can make an alias in your shell. That is really odd though that awk is not already in that path. – squiguy Dec 24 '12 at 10:01

How can I use grep to get the line number without the output?

3 Answers3