Question

(C++/Linux) I am a little confused as to what the first line in the main exactly does. I am also in need of clarity about all the possibilities in the if statement and what they mean and correspond to (all in the code below). Thank you.

#include <iostream>
#include <unistd.h>

int main()
{
        pid_t id = fork();

        if(id == -1) {
                std::cout << "Error creating process\n";
        } else if (id == 0) {
                std::cout << "I am a child process!\n";
        } else {
                std::cout << "I just became a parent!\n";
        }

        return 0;
}

Answer 1

fork() function will create a new process and store the id from the OS library or os will allot id if id is negative -1 then error will be thrown to creating process, if id is 0 then that process will be called a child process or else any non-zero and positive process number eg 2546 or 5542 will be a parent process.

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