$ perl -MPath::Tiny -le " print scalar gmtime( path( shift )->stat->mtime ) " .
Mon Sep 14 09:38:52 2015

$ perl -MPath::Tiny -le " print scalar gmtime( path( shift )->stat->mtime ) " ..
Fri May 29 06:13:23 2009

$ perl -MFile::stat -le " print scalar gmtime( stat( shift )->mtime ) " .
Mon Sep 14 09:38:52 2015

$ perl -MFile::stat -le " print scalar gmtime( stat( shift )->mtime ) " ..
Fri May 29 06:13:23 2009

$ perl -MPath::Tiny -le " print scalar gmtime( path( shift )->stat->mtime ) " NUL
Error stat on 'NUL': Invalid argument at -e line 1.

$ perl -MFile::stat -le " print scalar gmtime( stat( shift )->mtime ) " NUL
Can't call method "mtime" on an undefined value at -e line 1.