ATOF(3P)                                            POSIX Programmer's Manual                                           ATOF(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       atof - convert a string to a double-precision number

SYNOPSIS
       #include <stdlib.h>

       double atof(const char *str);


DESCRIPTION
       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.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       The  atof() function is subsumed by strtod() but is retained because it is used extensively in existing code. If the num-
       ber is not known to be in range, strtod() should be used because atof() is not required to perform any error checking.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       strtod(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                      ATOF(3P)