triggering another program to run using serial port

[infineonintern]

hello, is it possible that when i run a program on computer A, it will trigger the serial port of computer B so that another program in computer B will run? The computers are connected by a null modem cable and both programs are written in C++ language and is running in a console application.

The programs are actually a kind of text file transferring between two computers where computer B will read a content from an existing textfile in that computer and send it line by line untill the end of line to computer A and exits itself. Computer A will log the textfile content into a newly created textfile.

The program is currently working but i have to run the program in computer A first which will start polling for an input and then i go to computer B to click and run the program so that it will start transferring.

My question is, can i do it in a way that when i run the program in computer A, it will automatically trigger the program in computer B to run without having to click on the program in computer B to run? If it is possible, how can i do it in c++? Does the program in computer B have to be in a sleep mode? I can paste the code for the programs in computer A and computer B if needed. Thanks!

[helios]

I'm pretty sure you'd need a program on computer B listening on the serial port.