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How do I list top or bottom 10 lines from the line that matched the word 'error' in a file.

I'm using grep 'error' /var/log/logfile.log > errors to print and save the lines that matched the word 'error' in to the file called 'errors'. How could I change this to suite my requirement?. Anybody has any idea?

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1 Answer 1

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Displaying lines before/after/around the match using grep -A, -B and -C

-A is the option which prints the specified N lines after the match as shown below.

-B is the option which prints the specified N lines before the match.

-C is the option which prints the specified N lines before the match. In some occasion you might want the match to be appeared with the lines from both the side. This options shows N lines in both the side(before & after) of match.

Source: http://www.thegeekstuff.com/2009/03/15-practical-unix-grep-command-examples/ (Also I would recommend you to read the full blog post)

so, the command should be like grep -C 10 'error'

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  • awesome!!!. It's really more than the one what I want and the link is really useful. Again a small thing, a file may have many lines matched the word and is it possible to differentiate/separate with some hashes or spaces or with something.
    – user3215
    Mar 20, 2011 at 14:54
  • Thanks! You can accept the answer as accepted. Regarding your question, are you trying to match selectively? I am not sure if that can be done by grep somehow without an example. I would suggest you to ask a different question explaining with an example so that others can help you out.
    – Ashfame
    Mar 20, 2011 at 15:40
  • @user3215 if you want the first match or the last match, try piping through head or tail, respectively. Eg grep -C 10 'error'|head -n 10
    – djeikyb
    Mar 20, 2011 at 16:09
  • @djeikyb I think he actually wants to grep the "error" with a certain pattern around that word.
    – Ashfame
    Mar 20, 2011 at 16:12
  • Eg: after the first 10 lines of from the line contains error, give some space/hashes and then print next 10 lines
    – user3215
    Mar 21, 2011 at 2:13

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