how do i simulate a null character from the keyboard?

how do i simulate a null character from the keyboard within an a.exe? why is ctrl-d a logout command instead of NULL? -ethan __ Do You Yahoo!? Yahoo! Sports - Coverage of the 2002 Olympic Games http://sports.yahoo.com -- Unsubscribe info:

Cygwin seg faults using dyn. memory

cygwin seg faults when i attempt to assign values to allocated dynamic memory. The same code isn't seg-faulting on a Compaq Tru64 UNIX V5.1A machine. is there a setting where the heap needs to be adjusted? are there libraries i need to include that i haven't? here's the embarassingly simple

cannot open output file a.exe: Permission denied

I was trying to compile a simple multi-file C++ program when i got this error message: /usr/lib/gcc-lib/i686-pc-cygwin/2.95.3-5/../../../../i686-pc-cygwin/bin/ld: cannot open output file a.exe: Permission denied collect2: ld returned 1 exit status i moved all the files into a different directory