d:\temp>perl -e"$SIG{"__WARN__"} = sub {push @err,$_[0]; print STDERR $_[0]}; while(<>) {1};print qq<---\n @err>" file1 file2 file3
Can't open file1: No such file or directory at -e line 1.
Can't open file2: No such file or directory at -e line 1.
Can't open file3: No such file or directory at -e line 1.
---
 Can't open file1: No such file or directory at -e line 1.
 Can't open file2: No such file or directory at -e line 1.
 Can't open file3: No such file or directory at -e line 1.

d:\temp>