Manual Pages  — ATOF

atof – convert ASCII string to double

LIBRARY SYNOPSIS DESCRIPTION IMPLEMENTATION NOTES ERRORS SEE ALSO STANDARDS HISTORY

Standard C Library (libc, -lc)

#include <stdlib.h>

double
atof(const char *nptr);

The atof() function converts the initial portion of the string pointed to by nptr to double representation.

It is equivalent to:

strtod(nptr, (char **)NULL);

The decimal point character is defined in the program's locale (category LC_NUMERIC).

The atof() function is not thread-safe and also not async-cancel-safe.

The atof() function has been deprecated by strtod() and should not be used in new code.

The function atof() need not affect the value of errno on an error.

The atof() function conforms to IEEE Std 1003.1-90 ("POSIX.1"), ISO/IEC 9899:1990 ("ISO C90"), and ISO/IEC 9899:1999 ("ISO C99").

The atof() function appeared in AT&T v1 .