$ perl -e'print <<"__EOI__";
POST /zzz.cgi HTTP/1.0
Host: www.example.com
Content-Length: 11

key=Ch\xE2teau
__EOI__
' | nc www.example.com 80 | od -c
00000   H   T   T   P   /   1   .   1       2   0   0       O   K  \r
00020  \n   D   a   t   e   :       W   e   d   ,       2   8       A
00040   p   r       2   0   1   0       2   2   :   1   0   :   1   4
00060       G   M   T  \r  \n   S   e   r   v   e   r   :       A   p
00100   a   c   h   e  \r  \n   V   a   r   y   :       A   c   c   e
00120   p   t   -   E   n   c   o   d   i   n   g  \r  \n   C   o   n
00140   t   e   n   t   -   L   e   n   g   t   h   :       1   1   8
00160  \r  \n   C   o   n   n   e   c   t   i   o   n   :       c   l
00200   o   s   e  \r  \n   C   o   n   t   e   n   t   -   T   y   p
00220   e   :       t   e   x   t   /   h   t   m   l   ;       c   h
00240   a   r   s   e   t   =   i   s   o   -   8   8   5   9   -   1
00260   5  \r  \n  \r  \n   <   t   i   t   l   e   >   T   e   s   t
00300   <   /   t   i   t   l   e   >  \n   <   f   o   r   m       m
00320   e   t   h   o   d   =   "   P   O   S   T   "   >  \n   <   i
00340   n   p   u   t       t   y   p   e   =   "   t   e   x   t   "
00360       n   a   m   e   =   "   k   e   y   "       v   a   l   u
00400   e   =   "   C   h 342   t   e   a   u   "   >  \n   <   i   n
00420   p   u   t       t   y   p   e   =   "   s   u   b   m   i   t
00440   "   >  \n   <   /   f   o   r   m   >  \n
00453