signbit(3p) - phpMan

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

PROLOG
       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
       signbit - test sign
SYNOPSIS
       #include <math.h>
       int signbit(real-floating x);

DESCRIPTION
       The signbit() macro shall determine whether the sign  of  its  argument
       value is negative. NaNs, zeros, and infinities have a sign bit.
RETURN VALUE
       The  signbit()  macro  shall return a non-zero value if and only if the
       sign of its argument value is negative.
ERRORS
       No errors are defined.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       fpclassify(), isfinite(), isinf(), isnan(), isnormal(), the Base  Defi-
       nitions volume of IEEE Std 1003.1-2001, <math.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, Copyright (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.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                          SIGNBIT(3P)