finding position of first occurence of 3 different stopping criteria

imlou has asked for the wisdom of the Perl Monks concerning the following question:

I'm using the function index to find the position of a couple of stopping strings. Say I have 3 different stopping strings. ie. $end1, $end2, $end3 In a file I need to find the first occurence of either one. Could I do something like this.

$startcod = index($seq, $start);
print "$startcod\n";

$endcod = index($seq, $end1 || $end2 || $end3, $startcod);
print "$endcod\n";
[download]

Or is there another way to do it. Thanks!

Comment on finding position of first occurence of 3 different stopping criteria Select or Download Code

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Re: finding position of first occurence of 3 different stopping criteria by Not_a_Number (Prior) on Sep 21, 2003 at 19:53 UTC
You could try something like this: `my $seq = "012345678WW89YYabcdeZZ"; my $start = 'WW'; my @ends = qw (XX YY ZZ); my $end = '(' . join ( '\|', @ends ) . ')'; if ( $seq =~ /$start.*?$end/ ) { print "start: $-[0] end: $-[1]"; }` [download] dave	[reply] [d/l]
Re: finding position of first occurence of 3 different stopping criteria by kvale (Monsignor) on Sep 21, 2003 at 19:35 UTC
Try a regexp: `my $extract = $1 if $text =~ /^(.*?)($end1\|$end2\|$end3)/;` [download] -Mark	[reply] [d/l]
Re: Re: finding position of first occurence of 3 different stopping criteria by runrig (Abbot) on Sep 21, 2003 at 21:18 UTC
If you just want the position of the start of match, then it's as easy as: `print "Matched at $-[1]\n" if $text =~ /^.*?($end1\|$end2\|$end3)/;` [download] See perlvar for @- and @+ variables. Update: and this is along the same lines as Not_a_Number's post below. sorry for the redundancy...	[reply] [d/l]
Re: finding position of first occurence of 3 different stopping criteria by shenme (Priest) on Sep 21, 2003 at 20:01 UTC
Getting back to capturing what matched and where, but use Not a Number's way of constructing the inner match: `my $s2 = '$endcod = index($s2eq, $end1 \|\| $end2 \|\| $end3, $s2tart +cod);'; while( $s2 =~ m/(end\|dex\|art)/g ) { printf " Found '%s' at %d\n", $1, pos($s2); }` [download] Outputs: Found 'end' at 4 Found 'dex' at 15 Found 'end' at 27 Found 'end' at 36 Found 'end' at 45 Found 'art' at 55	[reply] [d/l]