atof man page

atof ā€” convert a string to a double


#include <stdlib.h>

double atof(const char *nptr);


The atof() function converts the initial portion of the string pointed to by nptr to double. The behavior is the same as

strtod(nptr, NULL);

except that atof() does not detect errors.

Return Value

The converted value.


For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
atof() Thread safety MT-Safe locale

Conforming to

POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.

See Also

atoi(3), atol(3), strfromd(3), strtod(3), strtol(3), strtoul(3)


This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at

Referenced By

atoi(3), mawk(1), strfromd(3), strtod(3), strtol(3), strtonum.3bsd(3), strtoul(3).

2016-12-12 GNU Linux Programmer's Manual