Exit Status In POSIX-compliant Systems

Choosing the right exit status for success or failure opreation in the program is critical.

In POSIX-compliant systems, there are 2 exit codes. 0 indicate a success and 1 indicate a failures.

I use {0,1} instead of a macro {EXIT_SUCCESS, EXIT_FAILURE} that defined in stdlib.h because it’s the same things and it’s less type for me.