#!/usr/bin/perl
# ===========================================================================
#   fetchurl.pl - a very simple replacement for wget -O <file> <url>
#   Usage:  fetchurl.pl <file> <url>
# ===========================================================================

package main;

use 5.006_000;
use diagnostics;
use strict;
use warnings;


# ===========================================================================
#	Modules
# ===========================================================================

use HTTP::Request;
use LWP::UserAgent;


# ===========================================================================
#	Subroutines
# ===========================================================================

sub FetchFile($$)
{
	my ($src_url, $dst_file) = @_;
	
	my $error = '';
	my $ua = LWP::UserAgent->new;
	my $request = HTTP::Request->new(GET => $src_url);
	
	# issue GET request
	my $response = $ua->request($request);
	if ($response->is_success)
	{
		# write HTML content to file
		if (open(FH_OUT, "> $dst_file"))
		{
			print FH_OUT $response->content;
			close(FH_OUT);
		}
		else
		{
			$error = "can't open datafile '$dst_file' ($!)";
		}
	}
	else
	{
		$error = "attempt to retrieve '$src_url' failed (" . $response->status_line . ")";
	}
	
	if ($error ne '')
	{
		print STDERR "Error: $error\n";
	}
	
	return ($error eq '');
}


sub DoUsage()
{
    print STDERR "Usage: fetchurl <file> <url>\n";
    print STDERR "  <file>  file to create or overwrite\n";
    print STDERR "  <url>   URL to fetch.\n";    
}


sub Main()
{
	my @arguments = @ARGV;
	
	# exactly two arguments must be supplied (<file> and <url>)
	if (scalar(@arguments) != 2)
	{
		DoUsage();
		exit 0;
	}
	
	my $dst_file = $arguments[0];
	my $src_url = $arguments[1];
	
	# check if the source URL argument looks like a URL
	if (not ($src_url =~ /^https?:\/\/[\w\-.]+(\/\S+)?$/))
	{
		print STDERR "Error: fetchurl doesn't recognize '$src_url' as a URL.\n";
		DoUsage();
		exit 0;
	}
	
	# fetch the URL and write it to the file
	my $success = FetchFile($src_url, $dst_file);
	
	return $success;
}
	

# ===========================================================================
#	Call Main
# ===========================================================================

Main();