Can argc be zero on a POSIX system?

Question

Given the standard definition for the main program:

int main(int argc, char *argv[]) {
   ...
}

Under which circumstances can argc

Answer 1

whenever you want to run any executable like ./a.out it will have one argument thats the program name. But It is possible to run a program with argc as zero in Linux, by executing it from another program that calls execv with an empty argument list.

for e.g

int main() {
    char *buf[] = { NULL };
    execv("./exe", buf); /* exe is binary which it run with 0 argument */
    return 0;
}