There is always another way to do it. ;-)

The following is my method that works on Unix/Linux platforms. It relies on the properties of -F switch of ls
that appends a '/' character after directories, a '*' character after executables, etc.

use strict;
use warnings;
use Data::Dumper;

my @txt_files = map {m!(.*\.txt)[^/]*$!} split /\n/, `ls -F`;
                    #   ^txt only  ^want non-directories
                    #               and throw away the flag

print Dumper(\@txt_files);

my $num_files = $#txt_files + 1;
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