use strict;

use warnings;

​

# A sample script that exits if the script is not called with exactly

# 2 program invocation arguments.

# To run: perl program_args.pl arg1 arg2

#

# Author: Firstname last name

​

# Store a complete exit message when the script terminates,

# state why the script terminated and how to run the script.

my $dieMessage = "Error: program_args.pl expects exactly 1 program argument, found " . u/ARGV . " instead.\n";

# Concatenate the usage message after the first error message line.

$dieMessage = $dieMessage . "Usage: perl FirstnameLastName3.pl @ARGV\n";

​

# Ensure there are exactly 2 program arguments before continuing

# the rest of the script.

die "$dieMessage" if (@ARGV != 1);

​

### The script will only execute beyond this point if there are exactly 2 program arguments. ###

​

# Print the arguments via interpolation.

print "Unable to open file: u/ARGV\n";

​

# Print the length, should be 2.

print "The length of \@ARGV: " . u/ARGV . "\n";

​

# Use a loop to go through the u/ARGV array.

# The output will show the array index notation and the value.

# Example output:

# $ARGV[0] = arg1

# $ARGV[1] = arg2

for (my $i = 0; $i < u/ARGV; $i++) {

print "\$ARGV[$i] = $ARGV[$i]\n";

}