fabs(3) Library Functions Manual fabs(3) fabs, fabsf, fabsl - LIBRARY Math library (libm, -lm) #include double fabs(double x); float fabsf(float x); long double fabsl(long double x); glibc (. feature_test_macros(7)): fabsf(), fabsl(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE x. x. x NaN, NaN. x -0, +0. x , . . attributes(7). +----------------------------+----------------------------------------------------------+--------------------------+ | | | | +----------------------------+----------------------------------------------------------+--------------------------+ |fabs(), fabsf(), fabsl() | | MT-Safe | +----------------------------+----------------------------------------------------------+--------------------------+ C11, POSIX.1-2008. C99, POSIX.1-2001. , double, SVr4, 4.3BSD, C89. . abs(3), cabs(3), ceil(3), floor(3), labs(3), rint(3) Azamat Hackimov , Dmitry Bolkhovskikh , Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 31 2023 . fabs(3)