[Pdx-pm] regular expression

[darthsmily]

Thanks to everyone who helped me out with me regular expression troubles.

Tkil wrote:

>>>>>>"John" == John Sechrest <sechrest at peak.org> writes:
>>>>>>            
>>>>>>
>
>John> So regular expressions are greedy. So you have to provide more
>John> constraints.
>
>Note that Perl has exactly what is needed to turn a greedy quantifier
>into a non-greedy one: suffix the quantifier with a '?' character.
>
>In this case:
>
>| $ cat in.txt
>| keyword NeedThis_1(blah, bloh); keyword NeedThis_2(blah, bloh,foo, bar);
>
>Original expression:
>
>| $ perl -lnwe 'while ( /keyword (.*)\(/g ) { print $1 }' in.txt
>| NeedThis_1(blah, bloh); keyword NeedThis_2
>
>Non-greedy version (note ".*?" instead of ".*"):
>
>| $ perl -lnwe 'while ( /keyword (.*?)\(/g ) { print $1 }' in.txt
>| NeedThis_1
>| NeedThis_2
>
>John> You could say:
>John> keyword [0-9_A-Za-z]*]\(
>John> And limit it to  characters
>
>This is a pretty good suggestion anyway; most tokens are going to be
>alphanumeric+underscore ... which, as it turns out, is exactly what
>"\w" matches:
>
>| $ perl -lnwe 'while ( /keyword (\w+)/g ) { print $1 }' in.txt
>| NeedThis_1
>| NeedThis_2
>
>t.
>
>  
>