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

[Leroy Tennison]

Robert Citek wrote:
> 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
> 
> _______________________________________________
> http://www.ntlug.org/mailman/listinfo/discuss
> 

A different approach (admittedly wandering because it's not using grep) 
is an awk script:

$0 ~ "whatever" {print $0; exit;}