Question

Which is true about the fork ( ) system call ?

• A. It allocates memory
• B. It creates a child process
• C. It creates a program
• D. It creates machine code

Hint:

Think of fork() like a biological cell division. One process splits into two identical "cells" (processes). Use the return value to tell them apart: 0 for the child, and the Child's PID for the parent.

Answer 1

The Correct Option is B

The fork() system call is one of the most fundamental operations in UNIX-like operating systems for process management. 1. Primary Function: When a process calls fork(), the operating system creates a new process. This new process is called the child process, and the process that initiated the call is the parent process. 2. Mechanism of fork(): The child process is an exact duplicate of the parent process. It inherits:
• The parent's address space (code, data, and stack).
• Open file descriptors.
• Environment variables. After the call, both processes continue execution from the instruction immediately following the fork() call. 3. Why other options are incorrect:
• (1) Memory Allocation: While fork() requires the OS to allocate memory for the new process, its primary purpose is process creation. malloc() is specifically for memory allocation.
• (3) Program Creation: Programs are files on a disk. fork() creates a running instance (process).
• (4) Machine Code: Machine code is created by compilers, not system calls.