FABS(3) Linux Programmer's Manual FABS(3)
fabs - absolute value of floating-point number
#include <math.h> double fabs(double x);
The fabs() function returns the absolute value of the floating-point number x.
SVID 3, POSIX, BSD 4.3, ISO 9899
abs(3), ceil(3), floor(3), labs(3), rint(3) June 25, 1993 1