my $kakiko = "書き込む";

my $ponn = "dhcp-1945.nava21.ne.jp";

my $honbun = "テスト";

$kakiko =~ s/(\W)/'%' . unpack('H2', $1)/eg;

$ponn =~ s/(\W)/'%' . unpack('H2', $1)/eg;

$honbun =~ s/(\W)/'%' . unpack('H2', $1)/eg;

select(SOCKET); $|=1; select(STDOUT);

print SOCKET "POST /test/bbs.cgi HTTP/1.0\r\n";
print SOCKET "Referer: http://pc11.2ch.net/tech/\r\n";
print SOCKET "Cookie: NAME=; MAIL=; SPID(PON)=$ponn; expires=; path=/\r\n";
print SOCKET "Host: ${host}\r\n";
print SOCKET "Content-length: 101\r\n";
print SOCKET "\r\n";
print SOCKET "bbs=tech&key=1199977642&time=&submit=$kakiko&FROM=&mail=&MESSAGE=$honbun\r\n";

これでやったら書き込み確認になる(´･ω･`)
何がだめなんだろう