I know to search for longest string separated by 1's, I would use =~ /(1.*1)/, but here "." will pick 0's and 1's both, and I only want 1's. I tried few other combinations but didn't seem to work. any suggestions?

1* is equivalent to 1{0,}
1+ is equivalent to 1{1,}

And 1{1,}1 is just nonsense. It matches a minimum of two 1's, but certainly does not match the longest run of 1's in a string--it just matches the *first* run of 1's that has at least two 1's in it. For instance, 

use strict;
use warnings;
use 5.010;


my $str = '110011111111';
$str =~ s/1{1,}1/*/;
say $str;

--output:--
*0011111111

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In reply to Re: how to replace a matched pattern in a string with a different pattern of same length? by 7stud
in thread how to replace a matched pattern in a string with a different pattern of same length? by BhariD

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