atof(3p) — Linux manual page

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

PROLOG         top

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

NAME         top

       atof — convert a string to a double-precision number

SYNOPSIS         top

       #include <stdlib.h>

       double atof(const char *str);

DESCRIPTION         top

       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.1‐2017 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         top

       The atof() function shall return the converted value if the value
       can be represented.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

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

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       strtod(3p)

       The Base Definitions volume of POSIX.1‐2017, stdlib.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                          ATOF(3P)

Pages that refer to this page: stdlib.h(0p),  awk(1p)

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