Perl CGIで超簡易型の「確認君」を作る方法

#!/usr/bin/perl

# ↑
# サーバの環境により #!/usr/local/bin/perl

my $r_addr = $ENV{'REMOTE_ADDR'};
my $host = $ENV{'REMOTE_HOST'};
if ($host eq '') {
  $host = gethostbyaddr(pack('C4', split(/\./, $r_addr)), 2); # AF_INET = 2
}
my $ua = $ENV{'HTTP_USER_AGENT'};
my $ref = $ENV{'HTTP_REFERER'};

print "Content-type: text/html\n\n";
print <<"HTML";
<META http-equiv="Content-Type" content= "text/html; charset=utf-8">

$r_addr<BR>
$host<BR>
$ua<BR>
$ref<BR>

HTML

exit;

#!/usr/bin/perl

print "Content-type: text/html\n\n";
print "<pre>\n";

foreach $key (sort keys(%ENV)) {
  print "$key = $ENV{$key}<p>";
}
print "</pre>\n";