PID    PPID COMMAND         S
   4331    1423 bash            S
   4732    4331  \_ a.out       S
   4733    4732      \_ a.out   S
   4736    4733      |   \_ a.o S
   4737    4733      |   \_ a.o S
   4734    4732      \_ a.out   S
   4735    4732      \_ a.out   S

-> Il y aura donc 6 appels à a.out.