FABS(3) Linux Programmer s Manual FABS(3)
NAME fabs, fabsf, fabsl - absolute value of floating-point number
SYNOPSIS #include <math.h>
double fabs(double x); float fabsf(float x); long double fabsl(long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
fabsf(), fabsl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
DESCRIPTION The fabs() functions return the absolute value of the floating-point number x.
RETURN VALUE These functions return the absolute value of x.
If x is a NaN, a NaN is returned.
If x is -0, +0 is returned.
If x is negative infinity or positive infinity, positive infinity is returned.
ERRORS No errors occur.
CONFORMING TO C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.
SEE ALSO abs(3), cabs(3), ceil(3), floor(3), labs(3), rint(3)
COLOPHON This page is part of release 3.22 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/.