read(STDIN, $GN_QUERY, 100); doesn't behave on Windows IIS

[Joe Burnett]

Hello,

I am using the following perl read function to read form information
from a client web page:

read(STDIN, $GN_QUERY, 100);

Everything works fine on a Linux/Apache server. I get the expected
parameter and value from the form.

When I use the same function on Windows/IIS, the perl script stalls.
When I change it to:

read(STDIN, $GN_QUERY, 0);

I get no information on Windows/IIS. When I change it to:

read(STDIN, $GN_QUERY, 20);

I get truncated information. When I change it to

read(STDIN, $GN_QUERY, 33);

I get exactly what I need. Problem is, I can't anticipate what a user is
going to type.
Has anyone seen this? How can I solve or workaround the problem?

Thanks in advance,

Joe Burnett