Substitute (s///) a set of times

[jryan]

This subroutine will s/// a set number of times.

The obvious solution would seem to be: s/\Gpattern/blah/ while $count--, but that does not work because \G only works with m//, and s/(a)/<$1$1>/ while $count-- would restart the match each time at the beginning. (pos=0)

Usage is: subtimes($string, $number_of_times, $pattern, $string_to_substitute). You can include $dollar variables in $string_to_substitute, just make sure to remember to backslash the dollar variable in the string.

For instance, this: print subtimes("ababa", 2, qr/(a)/,"<\$1\$1>"); would print "<aa>b<aa>ba".

Update: Fixed a bug.

print subtimes($string, 2, qr/(a)/,"<\$1\$1>");

sub subtimes {
    my ($string, $count, $find, $tosub) = @_;
    no strict "refs";
    
    my $newstring;
    while ($count--) {
        next unless $string =~ /($find)/;
        my ($num,%res) = 2;
        $res{$num++}=$$num while defined $$num;
        my ($matched, $startoffset, $endoffset, $temp) = ($1, $-[0], $
++[0], $tosub);

        $temp =~ s/\$(\d+)/my $r=$1;$r++;$res{$r}/ge;
        $newstring .= substr($string, 0, $startoffset).$temp;
        substr($string, 0, $endoffset) = '';
    }
    return $newstring.$string;
}