Always use strictures (use strict; use warnings). In this case you would have been told that /^*.tmp$/:

^* matches null string many times in regex; marked by <-- HERE in m/^* <-- HERE .tmp$/ at ...

^ anchors the start of the string and it is meaningless to follow it by * which matches the previous match 0 or more times. Actually you should probably omit the anchor and the (implied) 'skip junk' match in any case. Just use /\.tmp$/.