STRTOD(3) OpenBSD Programmer's Manual STRTOD(3)NAME
strtod, strtof, strtold - convert ASCII string to double, float or long
double
SYNOPSIS
#include <math.h>
#include <stdlib.h>
double
strtod(const char *nptr, char **endptr);
float
strtof(const char *nptr, char **endptr);
long double
strtold(const char *nptr, char **endptr);
DESCRIPTION
The strtod() function converts the initial portion of the string pointed
to by nptr to double representation. The strtof() function converts the
initial portion of the string pointed to by nptr to float representation.
The strtold() function converts the initial portion of the string pointed
to by nptr to long double representation.
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.
RETURN VALUES
The strtod(), strtof() and strtold() functions return the converted
value, if any.
If endptr is not NULL, a pointer to the character after the last
character 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
returned (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.
ERRORS
[ERANGE] Overflow or underflow occurred.
SEE ALSOatof(3), atoi(3), atol(3), strtol(3), strtoul(3)STANDARDS
The strtod() function conforms to ANSI X3.159-1989 (``ANSI C''). The
strtof() and strtold() functions conform to ANSI/ISO/IEC 9899-1999
(``ANSI C99'').
OpenBSD 4.9 September 13, 2008 OpenBSD 4.9
