I'm using a while loop to iterate over some text to find all the instances of a pattern match. When I do the substitution on the match, the process hangs (some how I've created an infinite loop?) I thought perhaps it was the "[]" characters in one of the variables that was causing problems on interpolation but escaping them didn't help. Is there a better way to substitute text on multiple matches when you need match specific substitutions? 

while ($str =~ /<tag1[^>]*>\s*<tag2>\s*<tag3>([^<]*)<\/endtag3>/gsi) {
            ++$a;
            $b = $1;
            $b = $b . " [ $c-$a]";
            $str =~ s/(<tag1[^>]*>\s*<tag2>\s*)<tag3>[^<]*<\/endtag3>/
+$1<tag3>$b<\/endtag3>/si;
}

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In reply to while loop w/match is hanging by Anonymous Monk

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