[NTLUG:Discuss] in a world where grep doesn't have the -m (match) option..

[Robert Citek]

On Tue, Mar 25, 2008 at 5:03 PM, Chris Cox <cjcox at acm.org> wrote:
> Richard wrote:
>  > Chris Cox wrote:
>  >> Richard wrote:
>  >>
>  >>> ..how would one go about stopping a grep after the first match? <snippage>
>  >> <snippage>
>  >>
>  >> grep 'whatever' file | head -1
>  >> (that's a minus one)
>  >>
>  > AH YES!!  That's brilliant!   It would cause the search to continue..but
>  > WOULD get the job done.  Thanks Chris!
>  >
>
>  Shouldn't continue.  Should terminate after a full buffer containing
>  the matched string goes to the head command.

For example:

$ time -p yes hello | grep hello | head -10000000 | wc -l
10000000
real 2.04
user 2.40
sys 0.30

$ time -p yes hello | grep hello | head -1 | wc -l
1
real 0.01
user 0.01
sys 0.00

$ time -p yes hello | grep -m 1 hello | wc -l
1
real 0.00
user 0.00
sys 0.00

Regards,
- Robert