#!/usr/bin/perl

###############################################
#   cnt11.cgi
#      V1.0 (2003.10.14)
#                     Copyright(C) CGI-design
###############################################

require './gifcat.pl';

$base = './cntdata';			#データ格納ディレクトリ
$lockfile = "$base/lock";		#ロック

###
@pair = split(/&/,$ENV{'QUERY_STRING'});
foreach (@pair) {
	($n,$val) = split(/=/);
	$in{$n} = $val;
}
$id = $in{'id'};
$cnt = $in{'n'};
if (!$id) {$id = 'count';}

$addr = $ENV{'REMOTE_ADDR'};
$cntfile = "$base/$id.txt";
if (-e $cntfile) {
	&lock;
	open IN,"$cntfile";		($cnt,$paddr) = split(/<>/,<IN>);	close IN;
	if ($addr ne $paddr) {
		$cnt++;
		open OUT,">$cntfile";	print OUT "$cnt<>$addr<>";		close OUT;
	}
	&unlock;
}
else {open OUT,">$cntfile";		print OUT "$cnt<>$addr<>";		close OUT;		chmod(0666,$cntfile);}

$size = length($cnt);
if ($size < 4) {$cnt = sprintf("%04d",$cnt); $size = 4;}

print "Content-type: image/gif\n\n";
foreach (0 .. $size-1) {
	$n = substr($cnt,$_,1);
	$n = "$base/$n.gif";
	push (@img,$n);
}
binmode(STDOUT);
print &gifcat'gifcat(@img);
exit;

###
sub lock {
	$retry = 3;
	if (-e $lockfile) {
		$locktime = (stat($lockfile))[9];
		if ($locktime < time - 60) {&unlock;}
	}
	while (!mkdir($lockfile, 0755)) {
		if (--$retry < 0) {exit;}
		sleep(1);
	}
}
###
sub unlock {rmdir($lockfile);}