There seems to be a problem with Process.get*Stream() where * is Input, Output, or Error. I noticed my C program wasn't able to get input from stdin from the java program that called it. I lookd at UNIXProcess.java and in the constructor found something that didn't look quite right:

    UNIXProcess(String cmdarray[], String env[]) throws java.io.IOException {

stdin_fd = new FileDescriptor();
stdout_fd = new FileDescriptor();
stderr_fd = new FileDescriptor();

Shouldn't this be:

    UNIXProcess(String cmdarray[], String env[]) throws java.io.IOException {

stdin_fd = FileDescriptor.in; // new FileDescriptor();
stdout_fd = FileDescriptor.out; // new FileDescriptor();
stderr_fd = FileDescriptor.err; // new FileDescriptor();

?

I tried this and my problem was solved.

I hope to be proven wrong since this seems to be a very fundamental bug.