Re: regexp help -- grab almost a whole string

What I need is a single regexp that will get the result the first time. It is to be returned from a subroutine kinda like this:

sub get_regexp {
  if ($blah) 
    $regexp = qr {};
  elsif ($blahblah) 
    $regexp = qr {};
}
[download]

calling program

$REGEXP = get_regexp($ip);
($circuit_id) = $if_descr =~ $REGEXP;
[download]

I want to get the correct result with one regexp without having to do any cleanup after the fact (ie removing the dot in a different step).

There must be a way to do this? If not, I will simply leave the dot in.

TDR

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Re^2: regexp help -- grab almost a whole string by kennethk (Abbot) on May 19, 2009 at 19:58 UTC
Since your strings are separated, they must be captured in separate buffers and there is no way to join them with just a matching regular expression. If you change the calling program to implement the join solution I suggested above, it will not break existing behavior, except that failed matches will store a null string ("") in $circuit_id in place of an undef (both of which still evaluate false). If you cannot change the calling program, then I see no solution. `$REGEXP = get_regexp($ip); $circuit_id = join q{}, $if_descr =~ $REGEXP;` [download]	[reply] [d/l]
Re^2: regexp help -- grab almost a whole string by grizzley (Chaplain) on May 20, 2009 at 05:57 UTC
I think I did similar mistake while designing new test system at work. The assumption was, that every value can be tested and checked with a regexp. `$regexp = ...; if($value !~ /$regexp/) { $err .= "wrong value ($value)" }` [download] Everything was fine. And then came the issue with integer range, i.e. value must be integer between 0 and 12800... Now I think about redesigning the engine to accept sub reference instead of regexp: `$subref = ...; if(! &$subref($value)) { $err .= "wrong value ($value)" }` [download] because the only reasonable way of fixing it is to abandon assumption about "regexp can match even the universe" (pity, I like regexps...)	[reply] [d/l] [select]
Re^2: regexp help -- grab almost a whole string by Polyglot (Chaplain) on May 20, 2009 at 03:27 UTC
I'm not certain why it must be a "single regexp", but this will do the job in a single line of execution: if ($if_desc =~ /(DHEC)\.?(\w+)/) {$circuit_id = "$1$2"}; Would this satisfy your requirement? Blessings, ~Polyglot~	[reply]