Counter not increasing inside a for using fork()

I'm working on a little project here and one of the parts requires me to do something if a flag is on and other thing is the flag is off concurrently (using fork()). Althought I know this could bring mutex problems, I cannot seem to get it working. I don't think I ever get mutex anyway.

A piece of my code looks like this:

int i=0;
pid_t pid;
char c[1];
for(i=0;i<len;i++)
{
    pid=fork();
    if(pid)
    {
        wait(&w);
    }
    else
    {
        read(fd,&c,1);
        printf("I'm son %d, read: %s, pos value: %d\n",getpid(),c,pos);
        if(pos==0)
        {
           printf("I'm son %d, writing out in out1.txt\n",getpid());
           //some writing instructions...
           pos=1;
        }
        else
        {
           printf("I'm son %d, writing out in out2.txt\n",getpid());
           //some writing instructions...
           pos=0;
        }
        exit(0);
    }
}

The problem is that I'm always getting in the same if, thus, I always write only in one of the files and I need to alternate the writing between two files.

Actual output:

I'm son <NUMBER>, writing out in out1.txt
I'm son <NUMBER>, writing out in out1.txt
I'm son <NUMBER>, writing out in out1.txt
I'm son <NUMBER>, writing out in out1.txt
I'm son <NUMBER>, writing out in out1.txt

Desired output:

I'm son <NUMBER>, writing out in out1.txt
I'm son <NUMBER>, writing out in out2.txt
I'm son <NUMBER>, writing out in out1.txt
I'm son <NUMBER>, writing out in out2.txt
I'm son <NUMBER>, writing out in out1.txt

Thanks!