$ cat 691617.pl
#!/usr/bin/perl

use strict;
use warnings;
use Getopt::Long;

my $help;
my $test;
my $file;

GetOptions(
  "help|?"   => \$help,
  "t|test"   => \$test,
  "f|file=s" => \$file
) or die "arg error";

die "No such file '$file'" if ($file && ! -f $file);

1;

__END__

$ cat 691617.t
use strict;
use warnings;

use Test::More;
use Test::Cmd;
plan tests => 7;


my $test = Test::Cmd->new(
  prog        => '691617.pl',
  interpreter => '/usr/bin/perl',
  workdir     => '',
);


# These tests are expected to pass
$test->run(args => '-f 691617.pl');
ok($? == 0, "executing 691617.pl -f 691617.pl");

$test->run(args => '-t');
ok($? == 0, "executing 691617.pl -t");

$test->run(args => '--help');
ok($? == 0, "executing 691617.pl --help");

$test->run(args => '?');
ok($? == 0, "executing 691617.pl ?");


# These tests are expected to fail
$test->run(args => '-g');
ok($? != 0, "executing 691617.pl -g - expected failure");

$test->run(args => '-f no_such_file');
ok($? != 0, "executing 691617.pl -f no_such_file - - expected failure");

$test->run(args => '-f');
ok($? != 0, "executing 691617.pl -f <missing argument> - expected failure");

__END__

$ prove 691617.t
691617....ok
All tests successful.
Files=1, Tests=7,  1 wallclock secs ( 0.37 cusr +  0.05 csys =  0.42 CPU)
$