Question

In UNIX, which system call is used for inter process communication via shared memory ?

• A. pipe ( )
• B. msgget ( )
• C. shmget ( )
• D. semctl ( )

Hint:

UNIX IPC calls often start with the resource type: shm for Shared Memory, msg for Message Queues, and sem for Semaphores.

Answer 1

The Correct Option is C

Solution: UNIX provides several mechanisms for Inter-Process Communication (IPC). Each has specific system calls associated with its setup and management. 1. Analyzing System Calls:
• pipe(): Used to create a unidirectional data channel that can be used for inter-process communication.
• msgget(): Used to create or access a System V message queue.
• shmget(): The name stands for shared memory get. It is used to allocate a System V shared memory segment.
• semctl(): Used for semaphore control operations. 2. Shared Memory Mechanism: Shared memory is unique because it allows two or more processes to access the same physical memory space. This is the fastest form of IPC because it avoids copying data between the processes and the kernel. 3. Conclusion: The specific system call to initialize or find a shared memory segment is shmget().