What is a good general approach for deciding return values in C?

Question

My program is written in C for Linux, and has many functions with different patterns for return values:

1) one or two return n on success and -1

Answer 1

That is a matter of preference, but what I have noticed is the inconsistency. Consider this using a pre C99 compiler

#define SUCCESS  1
#define ERROR    0

then any function that returns an int, return either one or the other to minimize confusion and stick to it religiously. Again, depending on, and taking into account of the development team, stick to their standard.

In pre C99 compilers, an int of zero is false, and anything greater than zero is to be true. That is dependant on what standard is your compiler, if it's C99, use the stdbool's _Bool type.

The big advantage of C is you can use your personal style, but where team effort is required, stick to the team's standard that is laid out and follow it religiously, even after you leave that job, another programmer will be thankful of you.

And keep consistent.

Hope this helps, Best regards, Tom.