Convert char* to float / int in standard C

See more:

C

convert

Hi,
I'm working on a program in pure C, and I'm wondering how could I convert a char* to float / int. I know the ato? functions but what I expect is more than that; I'm looking for functions maybe like int str2float(char*, float*) / int str2int(char*, int*) which they return whether the given char* could be a legal numeric format.
I would get a 0.0 if I passed a normal "0.0" or a "something_else" to atof, and get a 3.14 if I passed a "3.14" or a "3.14balabala" to it, that would be terrible for me.