Limit on the number of arguments to main in C

Question

Is there a limit on the number of arguments that we pass to main() in C? As you all know, it is defined as int main(int argc, char *argv[]).

When I call the program, I can pass arguments like so:

$ prog.exe arg1 arg2 arg3.....argn

Is there an upper bound in the number of argument that we may supply to main() in this way?

Answer 1

According to the POSIX spec for exec, there is a macro ARG_MAX defined in <limits.h> which defines the maximum number of bytes for the arguments + environment variables.

But since C doesn't define anything about that, no, there isn't an inherent cross-platform limit. You have to consult your OS manual if it doesn't define that macro.