NAME
atof — convert a
string to a double-precision number
SYNOPSIS
#include
<stdlib.h>
double atof(const char *str);
DESCRIPTION
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.
The call atof (
str) shall be
equivalent to:
strtod(str,(char **)NULL),
except that the handling of errors may differ. If the value cannot be represented, the behavior is undefined.
RETURN VALUE
The atof () function shall return the
converted value if the value can be represented.
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
The atof () function is subsumed by
strtod(3) but is retained because it is used extensively
in existing code. If the number is not known to be in range,
strtod(3) should be used because
atof () is not required to perform any error
checking.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD <stdlib.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.