ffs(3) Library Functions Manual ffs(3) ffs, ffsl, ffsll - C (libc, -lc) #include int ffs(int i); int ffsl(long i); int ffsll(long long i); glibc (. feature_test_macros(7)): ffs(): Since glibc 2.12: _XOPEN_SOURCE >= 700 || ! (_POSIX_C_SOURCE >= 200809L) || /* glibc >= 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE Before glibc 2.12: none ffsl(), ffsll(): Since glibc 2.27: _DEFAULT_SOURCE Before glibc 2.27: _GNU_SOURCE ffs() ( ) i. 1, -- ( ) 32 64. ffsll() ffsl() , . 0, i . attributes(7). +----------------------------+----------------------------------------------------------+--------------------------+ | | | | +----------------------------+----------------------------------------------------------+--------------------------+ |ffs(), ffsl(), ffsll() | | MT-Safe | +----------------------------+----------------------------------------------------------+--------------------------+ ffs() POSIX.1-2001, POSIX.1-2008, 4.3BSD. ffsl() ffsll() GNU. memchr(3) () Azamat Hackimov , Dmitry Bolkhovskikh , Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () <>. Linux 6.9.1 2 2024 . ffs(3)