librecmc-gitorious/scripts/download.pl

#!/usr/bin/env perl
# 
# Copyright (C) 2006 OpenWrt.org
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#

use strict;
use warnings;
use File::Basename;
use File::Copy;

@ARGV > 2 or die "Syntax: $0 <target dir> <filename> <md5sum> [<mirror> ...]\n";

my $target = shift @ARGV;
my $filename = shift @ARGV;
my $md5sum = shift @ARGV;
my $scriptdir = dirname($0);
my @mirrors;
my $ok;

sub localmirrors {
	my @mlist;
	open LM, "$scriptdir/localmirrors" and do {
	    while (<LM>) {
			chomp $_;
			push @mlist, $_ if $_;
		}
		close LM;
	};
	open CONFIG, "<".$ENV{'TOPDIR'}."/.config" and do {
		while (<CONFIG>) {
			/^CONFIG_LOCALMIRROR="(.+)"/ and do {
				chomp;
				my @local_mirrors = split(/;/, $1);
				push @mlist, @local_mirrors;
			};
		}
		close CONFIG;
	};

	return @mlist;
}

sub which($) {
	my $prog = shift;
	my $res = `which $prog`;
	$res or return undef;
	$res =~ /^no / and return undef;
	$res =~ /not found/ and return undef;
	return $res;
}

my $md5cmd = which("md5sum") || which("md5") || die 'no md5 checksum program found, please install md5 or md5sum';
chomp $md5cmd;

sub download
{
	my $mirror = shift;
	my $options = $ENV{WGET_OPTIONS} || "";

	$mirror =~ s!/$!!;

	if ($mirror =~ s!^file://!!) {
		if (! -d "$mirror") {
			print STDERR "Wrong local cache directory -$mirror-.\n";
			cleanup();
			return;
		}

		if (! -d "$target") {
			system("mkdir", "-p", "$target/");
		}

		if (! open TMPDLS, "find $mirror -follow -name $filename 2>/dev/null |") {
			print("Failed to search for $filename in $mirror\n");
			return;
		}

		my $link;

		while (defined(my $line = readline TMPDLS)) {
			chomp ($link = $line);
			if ($. > 1) {
				print("$. or more instances of $filename in $mirror found . Only one instance allowed.\n");
				return;
			}
		}

		close TMPDLS;

		if (! $link) {
			print("No instances of $filename found in $mirror.\n");
			return;
		}

		print("Copying $filename from $link\n");
		copy($link, "$target/$filename.dl");

		if (system("$md5cmd '$target/$filename.dl' > '$target/$filename.md5sum'")) {
			print("Failed to generate md5 sum for $filename\n");
			return;
		}
	} else {
		open WGET, "wget -t5 --timeout=20 --no-check-certificate $options -O- '$mirror/$filename' |" or die "Cannot launch wget.\n";
		open MD5SUM, "| $md5cmd > '$target/$filename.md5sum'" or die "Cannot launch md5sum.\n";
		open OUTPUT, "> $target/$filename.dl" or die "Cannot create file $target/$filename.dl: $!\n";
		my $buffer;
		while (read WGET, $buffer, 1048576) {
			print MD5SUM $buffer;
			print OUTPUT $buffer;
		}
		close MD5SUM;
		close WGET;
		close OUTPUT;

		if ($? >> 8) {
			print STDERR "Download failed.\n";
			cleanup();
			return;
		}
	}

	my $sum = `cat "$target/$filename.md5sum"`;
	$sum =~ /^(\w+)\s*/ or die "Could not generate md5sum\n";
	$sum = $1;

	if (($md5sum =~ /\w{32}/) and ($sum ne $md5sum)) {
		print STDERR "MD5 sum of the downloaded file does not match (file: $sum, requested: $md5sum) - deleting download.\n";
		cleanup();
		return;
	}

	unlink "$target/$filename";
	system("mv", "$target/$filename.dl", "$target/$filename");
	cleanup();
}

sub cleanup
{
	unlink "$target/$filename.dl";
	unlink "$target/$filename.md5sum";
}

@mirrors = localmirrors();

unshift @mirrors, 'http://downloads.librecmc.com/sources';

while (!$ok) {
	my $mirror = shift @mirrors;
	$mirror or die "No more mirrors to try - giving up.\n";

	download($mirror);
	-f "$target/$filename" and $ok = 1;
}

$SIG{INT} = \&cleanup;