No reason other than uninformed DWIMmery. :-)
Thanks, your suggestion works perfectly in my real code. Changing the first line here (and leaving the second alone) to:
unless ( -f ( File::DosGlob::glob qq{"$template_file"} )[0] )
+{
produces:
ftf2: 'file_a.txt'
ftf2a: '"file_a.txt"'
ftf2b: 'file_a.txt' is okay.
ftf2: 'file_b.txt'
ftf2a: '"file_b.txt"'
ftf2b: 'file_b.txt' is okay.
ftf3: 'file_b.txt'
ftf3a: '"file_b.txt"'
ftf2b: 'file_b.txt' is okay.
ftf3: 'file_a.txt'
ftf3a: '"file_a.txt"'
8251b: File check, cannot access 'file_a.txt', No such file or directo
+ry