NAME
atof, atof_l
— convert ASCII string to
double
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<stdlib.h>
double
atof(const
char *str);
#include
<xlocale.h>
double
atof_l(const
char *str, locale_t
loc);
DESCRIPTION
The
atof()
function converts the initial portion of the string pointed to by
str to double
representation.
It is equivalent to:
strtod(str, (char **)NULL);
The decimal point character is defined in the program's locale
(category LC_NUMERIC).
While the
atof()
function uses the current locale, the
atof_l()
function may be passed a locale directly. See
xlocale(3) for more information.
IMPLEMENTATION NOTES
The atof() and
atof_l() functions are thread-safe and
async-cancel-safe.
The strtod() and
strtod_l() functions are recommended instead of
atof() and atof_l()
functions, especially in new code.
ERRORS
The function atof() need not affect the
value of errno on an error.
SEE ALSO
atoi(3), atol(3), strtod(3), strtol(3), strtoul(3), xlocale(3)
STANDARDS
The atof() function conforms to
IEEE Std 1003.1-1990 (“POSIX.1”),
ISO/IEC 9899:1990 (“ISO C90”),
and ISO/IEC 9899:1999
(“ISO C99”).