Automatically entering information to external program run from system() command

I'm working on an m-file that will call an external program using the system() command. Once the system() command is called, an external program (written in C) initializes. In the MATLAB command window, the external program appears and asks for input. I want to automate the process of entering the input by adding commands to the m-file, but cannot figure out how to do this. Successive calls to system() have no effect, as the command window just sits there waiting for me to manually enter input.

Does anyone have any ideas? Thanks in advance.

Answer 1

[Walter Roberson]

Java Robot Class if you want to be sure of it.

Depending on how the input is read, using I/O redirection might work,

system('theCommand < InputFile')

Answer 2

[Jason Ross]

If you have access to the C source code, it might be worth your time to build a better way of getting the data in, such as a command line switch or the ability to parse an input file. This way, the m-code just builds up the command you want to send to the system command and you bypass the whole messy input stage.