FreeBSD man pages : strtod (3)
STRTOD(3) FreeBSD Library Functions Manual STRTOD(3)
strtod - convert ASCII string to double
Standard C Library (libc, -lc)
strtod(const char *nptr, char **endptr);
The strtod() function converts the initial portion of the string pointed
to by nptr to 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 con-
sists of an ``E'' or ``e'', followed by an optional plus or minus sign,
followed by a sequence of digits.
Leading white-space characters in the string (as defined by the
isspace(3) function) are skipped.
The strtod() function returns 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
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.
[ERANGE] Overflow or underflow occurred.
atof(3), atoi(3), atol(3), strtol(3), strtoul(3)
The strtod() function conforms to ISO/IEC 9899:1990 (``ISO C89'').
The author of this software is David M. Gay.
Copyright (c) 1991 by AT&T.
Permission to use, copy, modify, and distribute this software for any
purpose without fee is hereby granted, provided that this entire notice
is included in all copies of any software which is or includes a copy or
modification of this software and in all copies of the supporting docu-
mentation for such software.
THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY REPRESEN-
TATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS
SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
Contact your vendor for a free copy of the source code to strtod() and
FreeBSD 4.8 June 4, 1993 FreeBSD 4.8