Shell Programming and Scripting

Hi,
There is a excutable program on Linux server and requires user to input some numbers to take them go through different steps to do things. I need to make the process from manual to automatic. I wrote a file that have each steps already typied. When user runs the program, I make them use below syntax:
program_name < Pretypied_Steps_file_name


It works each time I run it. But it hangs.. That means it would not be able to stop the program gracefully like I run it manually. I had to user ctrl & C to stop it.

Anybody know why?

Thanks in advance.

PS:
Actually, it gave a message at the begining of the program:
===stty: standard input: Inappropriate ioctl for device===
But it gave me the result I wanted except it hangs itself.

The prgram might be having infinite while loop until it gets some perticular number as input.

We need to find out from the prgmrmmer who wrote that
and find out what number we have to input for that prgram
to exit gracefully.

put that number at the end of all steps.