Program flow, fork() with logic

Question

I am trying to understand the flow of this simple C fork() code:

fork() && fork() || fork();
fork();
printf("forked ");

Output for me (g++) is:

forked forked forked forked forked forked forked forked forked 

Stepping over it doesn't really help me in understanding it.

Answer 1

fork() && fork() || fork();
^^^^^^^^^^^^^^^^
Parent forks a child with return value 0 for the child process. 
Since it is logical AND operator, the short-circuit evaluation applies, 
so the child doesn’t go further. Parent goes on forking again(right-hand-side of AND). 
There are 3 processes being composed of 2 children and 1 parent.



fork() && fork() || fork();
                    ^^^^^^
                    Again parent forks one more and since OR operator
                    doesn’t apply short-circuit for latter child
                    (due to return type which is 0 and left-hand-side of OR op.), 
                    the latter child forks as well. There are totally 5 processes.

 fork()[fourth]; doubles prior number of processes 5*2 = 10 processes totally exist.

Your output highly likely buffered. Try fprintf(stderr, "forked ");, fflush(stdout) or printf("forked\n”);.

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I think the following drawing helps more.