Pipe, Fork, and Exec - Two Way Communication Between Parent and Child Process

Question

An assignment in my Operating Systems class requires me to build a binary process tree by recursively calling exec on the same program. The goal is to split some arbitrary task

Answer 1

The first entry in your argv2 should be the name of the executable (just like your incoming argv[0].

char *argv2[] = {"two_way_pipes", "some random arg...", NULL};
execvp("two_way_pipes", argv2);

From the execvp man page:

The execv(), execvp(), and execvpe() functions provide an array of pointers to null-terminated strings that represent the argument list available to the new program. The first argument, by convention, should point to the filename associated with the file being executed. The array of pointers must be terminated by a NULL pointer.