SIGNBIT man page on Hurd

Man page or keyword search:  
man Server   6387 pages
apropos Keyword Search (all sections)
Output format
Hurd logo
[printable version]

SIGNBIT(3)		   Linux Programmer's Manual		    SIGNBIT(3)

NAME
       signbit - test sign of a real floating-point number

SYNOPSIS
       #include <math.h>

       int signbit(x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       signbit():
	   _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
	   _POSIX_C_SOURCE >= 200112L;
	   or cc -std=c99

DESCRIPTION
       signbit() is a generic macro which can work on all real	floating-point
       types.	It  returns a nonzero value if the value of x has its sign bit
       set.

       This is not the same as x < 0.0, because IEEE 754 floating point allows
       zero  to	 be  signed.   The  comparison	-0.0 < 0.0 is false, but sign‐
       bit(-0.0) will return a nonzero value.

       NaNs and infinities have a sign bit.

RETURN VALUE
       The signbit() macro returns nonzero if the sign of x is negative;  oth‐
       erwise it returns zero.

ERRORS
       No errors occur.

ATTRIBUTES
   Multithreading (see pthreads(7))
       The signbit() macro is thread-safe.

CONFORMING TO
       C99, POSIX.1-2001.  This function is defined in IEC 559 (and the appen‐
       dix with recommended functions in IEEE 754/IEEE 854).

SEE ALSO
       copysign(3)

COLOPHON
       This page is part of release 3.55 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU				  2013-07-04			    SIGNBIT(3)
[top]

List of man pages available for Hurd

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net