Question

Examine the code in process-fork-1.cpp. What is the value returned by the call to the fork() function if an error occurs and the OS is unable to create a child process?

#include
#include

int main() {
pid_t id = fork();
if(id == -1) {
std::cout << "Error creating process" << std::endl;
} else if (id == 0) {
std::cout << "I am a child process!" << std::endl;
} else {
std::cout << "I just became a parent!" << std::endl;
}
return 0;
}

Answer 1

In the provided C++ code, the 'fork()' function returns -1 if an error occurs during the creation of a child process.

Step-by-step explanation:

The code excerpt provided is from a C++ program that uses the fork() system call, which is common in UNIX-based operating systems for creating a new process.

The value returned by the fork() function if an error occurs is -1. If fork() successfully creates a child process, it returns the child's process ID to the parent and returns 0 to the child process.

The provided code handles this by checking if the returned value is -1 and prints an error message accordingly.