NAME

signbit — determine whether a floating-point number's sign is negative

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <math.h>

int
signbit(real-floating x);

DESCRIPTION

The signbit() macro takes an argument of x. It returns non-zero if the value of the argument's sign is negative, otherwise 0.

SEE ALSO

fpclassify(3), math(3)

STANDARDS

The signbit() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).