理解 fork() マルチプロセス

fork_test.c

# include <unistd.h>
# include <stdio.h>
int main ()
{
    pid_t fpid;
    int count=0;
    printf("This will not be forked.\n");
    fpid=fork();
    printf("Will be forked from here.\n");
    if (fpid < 0)
        printf("error in fork!");
    else if (fpid == 0) {
        printf("i am the child process, my process id is %d\n",getpid());

        count++;
    }
    else {
        printf("i am the parent process, my process id is %d\n",getpid());
        count++;
    }
    printf("count= %d\n",count);
    return 0;
}

gcc fork_test.c
a.out

 ./a.out
This will not be forked.
Will be forked from here.
Will be forked from here.
i am the parent process, my process id is 28355
count= 1
i am the child process, my process id is 28356
count= 1


 ./a.out
This will not be forked.
Will be forked from here.
i am the parent process, my process id is 28369
Will be forked from here.
count= 1
i am the child process, my process id is 28370
count= 1


 ./a.out
This will not be forked.
Will be forked from here.
i am the parent process, my process id is 28383
count= 1
Will be forked from here.
i am the child process, my process id is 28384
count= 1

./a.out
This will not be forked.
Will be forked from here.
i am the parent process, my process id is 28420
count= 1
Will be forked from here.
i am the child process, my process id is 28421
count= 1