Hello dear Monks!
Assuming you have the following string:
dddddddddBBBBBBBBBBBBDDDDDDDDBBBBBBBBBBBBBBddddddddddddddddddddBBBBBBB
+BBBBBBBDDBBBBBBBBddddddddddddd

[download]

I want to find the start and end positions of each of the B substrings. I have started coding this a bit, but I am obviously doing something wrong:
use strict;
use warnings;

my $seq = 'dddddddddBBBBBBBBBBBBDDDDDDDDBBBBBBBBBBBBBBdddddddddddddddd
+ddddBBBBBBBBBBBBBBDDBBBBBBBBddddddddddddd';

while($seq=~/(B+)/g)
{
    my $seg=$1;
    my $seg_length=length($seg);
    my $seg_start = index ($seq, $seg);
    my $seg_end=$seg_start+$seg_length;

    print $seg."|".$seg_start."-".$seg_end."\n";
}

[download]

In reply to Find the boundaries of a substring in a string by Anonymous Monk

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