diplay all lines before a match is found

csegau · 09-09-2010, 12:39 PM

Hi all,

my problem is as follow...

I have a file, and I have to display all the lines from the beginning of the file till a matching string is found.

I know grep with "-a", "-b" as option does exist, but it needs the number of lines to be printed in advance.
eg grep -b 10 "search_string" file
so it will print 10 lines before a match is found.

anomie · 09-09-2010, 12:58 PM

Is this homework?

There are a couple possible approaches:

whip together a contrived awk script to print lines until it reaches a particular string match (and then exit processing)
use two passes, the first with awk/sed/vi (to delete everything after string match), and the second with grep and its inversion option

Or something similar... you get the idea.

druuna · 09-09-2010, 01:07 PM

Hi,

Does indeed look a bit like homework

Have a look at sed, it can do all you ask for in one go (hint: line range).

crts · 09-09-2010, 01:08 PM

Code:

sed '/pattern/ q'