SIGNBIT(3) BSD Library Functions Manual SIGNBIT(3)NAMEsignbit — test sign
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <math.h>
int
signbit(real-floating x);
DESCRIPTION
The signbit() macro determines whether the sign of its argument value x
is negative. An argument represented in a format wider than its semantic
type is converted to its semantic type first. The determination is then
based on the type of the argument.
RETURN VALUES
The signbit() macro returns a non-zero value if the sign of its value x
is negative. Otherwise 0 is returned.
ERRORS
No errors are defined.
SEE ALSOfpclassify(3), isfinite(3), isnormal(3), math(3)STANDARDS
The signbit() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).
BSD October 29, 2003 BSD