What are IPC Mechanisms available in DOS and how can you make processes communicate in DOS?

Answer 1

In Actual the IPC stands for Inter Process Communication and that is a standard mechanism how processes intercommunicate in Operating System Environment .Means more than one process executing in environment need to share their outputs but as we know there DOS is think to be a non-preempted single user single processing environment ,we cannot assume so . I.e. there is no such a standard way of intercommunication . But still TSR's in DOS environment emulate the phenomenon of multiprocessing where we sometime work on system buffers like video buffer, keyboard buffer etc similar things can be defined for other processes which makes it possible to reside a persistent program buffer until the processes under dos tend to end up . For this we have to allocate a memory that will not be dumped until process state comes to termination. For further reference please study the notes written in Silberschatz Galvin's O/S Book where monolithic DOS environment is discussed in various columns of O/S properties.

Well you can't strictly have two programs running simultaneously in DOS, but DOS does allow some programs to install themselves permanently in memory. The easiest way for a program to communicate with a memory resident program, and bring it to life, is the one employed by DOS itself - arrange for the TSR to collar a software interrupt, and then communicate with it through that.