1SIGNBIT(3P)                POSIX Programmer's Manual               SIGNBIT(3P)
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PROLOG

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

12       signbit - test sign
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SYNOPSIS

15       #include <math.h>
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17       int signbit(real-floating x);
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DESCRIPTION

21       The signbit() macro shall determine whether the sign  of  its  argument
22       value is negative. NaNs, zeros, and infinities have a sign bit.
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RETURN VALUE

25       The  signbit()  macro  shall return a non-zero value if and only if the
26       sign of its argument value is negative.
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ERRORS

29       No errors are defined.
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31       The following sections are informative.
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EXAMPLES

34       None.
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APPLICATION USAGE

37       None.
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RATIONALE

40       None.
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FUTURE DIRECTIONS

43       None.
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SEE ALSO

46       fpclassify(), isfinite(), isinf(), isnan(), isnormal(), the Base  Defi‐
47       nitions volume of IEEE Std 1003.1-2001, <math.h>
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50       Portions  of  this text are reprinted and reproduced in electronic form
51       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
52       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
53       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
54       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
55       event of any discrepancy between this version and the original IEEE and
56       The  Open Group Standard, the original IEEE and The Open Group Standard
57       is the referee document. The original Standard can be  obtained  online
58       at http://www.opengroup.org/unix/online.html .
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62IEEE/The Open Group                  2003                          SIGNBIT(3P)
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