[thomashabets2]

If that's an error then so is passing in a non number.

So catch 22. You can only check for valid numbers if the number is valid?

[rbanffy]

If you pass a negative number as a string to a function that converts strings representing positive numbers into positive long integers, then yes, it should return an error status instead of the wrong result.

[thomashabets2]

Ah, I misunderstood what you meant by "is an error". Agree.

[imtringued]

That's the C way, yes.

[thomashabets2]

No. This is more like if strcmp compared null terminates strings, but can only compare strings that are in fact equal.