The regex match only had alphanumeric characters and underscores...

If your $pkt_file doesn't contain regular expressions, it's probably better to use \Q$pkt\E, because that'll prevent your program from doing unexpected things if $pkt does someday for whatever reason contain special characters. Similar to what AnomalousMonk wrote below about $1 $2 $3 etc. it's a "future-proofing" measure.

In reply to Re^3: How to use REGEX Match Variable from one 'While' String in Another 'While' String by Anonymous Monk
in thread How to use REGEX Match Variable from one 'While' String in Another 'While' String by GoldfishOfDoom

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