STRTOD(3) BSD Programmer's Manual STRTOD(3)
strtod, strtof - convert ASCII string to floating point
#include <stdlib.h> double strtod(const char *nptr, char **endptr); float strtof(const char *nptr, char **endptr);
These conversion functions convert the initial portion of the string pointed to by nptr to double or float representation, respectively. The expected form of the string is an optional plus ('+') or minus sign ('-') followed by a sequence of digits optionally containing a decimal- point character, optionally followed by an exponent. An exponent consists of an 'E' or 'e', followed by an optional plus or minus sign, followed by a sequence of digits. Leading whitespace characters in the string (as defined by the isspace(3) function) are skipped.
The strtod() and strtof() functions return the converted value, if any. If endptr is not NULL, a pointer to the character after the last charac- ter used in the conversion is stored in the location referenced by endptr. If no conversion is performed, zero is returned and the value of nptr is stored in the location referenced by endptr. If the correct value would cause overflow, plus or minus HUGE_VAL is re- turned (according to the sign of the value), and ERANGE is stored in errno. If the correct value would cause underflow, zero is returned and ERANGE is stored in errno.
[ERANGE] Overflow or underflow occurred.
atof(3), atoi(3), atol(3), strtol(3), strtoul(3)
The strtod() function conforms to ANSI X3.159-1989 ("ANSI C89").
The strtof() function was added to MirBSD in 2013. MirBSD #10-current February 9, 2014 1