Others seem to have interpreted this as "find all groups of one or more M's".

On the off chance that you actually meant 6 or more M's, try this modification of japhy's solution: 

my $seq = "...";
my @groups;
push @groups, [$-[0], $+[0]-1] while $seq =~ /M{6,}/g;
print "$_->[0] to $_->[1]\n" for @groups;

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(where the displayed positions are 0-based.)

In reply to Re: 'grouping' substrings? by ysth
in thread 'grouping' substrings? by Anonymous Monk

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