The server will send CONTENT_LENGTH bytes on
this file descriptor. Remember that it will give the CONTENT_TYPE of the data as well. The server is
in no way obligated to send end-of-file after the script reads
CONTENT_LENGTH
bytes.
a=b&b=c
.
In this case, the server will set CONTENT_LENGTH to 7 and CONTENT_TYPE to application/x-www-form-urlencoded. The first byte on the script's standard input will be "a", followed by the rest of the encoded string.
CGI - Common Gateway Interface
cgi@ncsa.uiuc.edu