#include <stdlib.h>long double strtof(const char * restrict start, char restrict ** restrict end);
strtof( ) was added by C99.
The strtof( ) function is similar to strtod( ) except that it returns a float value. If overflow occurs, then either HUGE_VALF or –HUGE_VALF is returned, and the global variable errno is set to ERANGE, indicating a range error. If start does not point to a number, no conversion takes place and zero is returned.
Related functions are atof( ), strtod( ), and strtold( ).