"Are there any errors? No (0) there are no errors." Not necessarily. It's just a (mostly POSIX and Linux kernel) convention to use 0 as "no error" result, but

"Are there any errors? No (0) there are no errors." Not necessarily. It's just a (mostly POSIX and Linux kernel) convention to use 0 as "no error" result, but there are plenty of code that returns 0 as an error and >0 for success. It has nothing to do with C language itself, as C functions let you return pretty much anything or nothing at all (void functions).