Your use of '^' is causing problems. '^' marks the beginning of an line and '$' marks the end of a line ("the buck stops here").

If the PMID is always numeric simply use:

if($foo->identifiers() =~ /PMID: (\d+)/) {print FH "$1\n";}

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Update: reworded post.

In reply to Re: Extracting web data by zek152
in thread Extracting web data by smandape1

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