Thanks Dave for the comment. !~ m/\.log$/ is working. Apparently you bring up a good point where $name.".log" is extra effort while the right condition has been included it.

For the suggestion to avoid reaadir and while loop, since I cannot sure which file would exist to be searched, and I need to print out whose additional files which not in the spec defined. How would I defined the condition in 'foreach' ?

if (-e 'abc' && -d _) {
    foreach my $entry (#other than <*.log>) {
        print OUTPUT ":E: $entry5 is  extra file/dir \n";
    }
}
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