flockfile(3) Library Functions Manual flockfile(3) flockfile, ftrylockfile, funlockfile - FILE stdio (libc -lc) #include void flockfile(FILE *filehandle); int ftrylockfile(FILE *filehandle); void funlockfile(FILE *filehandle); glibc ( feature_test_macros(7)): : /* Since glibc 2.24: */ _POSIX_C_SOURCE >= 199309L || /* glibc <= 2.23: */ _POSIX_C_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE stdio . FILE ( ) . FILE / . (: flock(2) lockf(3).) C . / / . . FILE / . . / stdio: getc_unlocked(3) putc_unlocked(3) getc(3) putc(3). flockfile() *filehandle *filehandle . funlockfile() . ftrylockfile() flockfile(). *filehandle . ftrylockfile() ( ) . . attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |flockfile(),| | MT-Safe | |ftrylockfile(),| | | |funlockfile()| | | +------------+------------------------------------+--------------------+ POSIX.1-2008. POSIX.1-2001. _POSIX_THREAD_SAFE_FUNCTIONS. unlocked_stdio(3) 3 . . : . 6.18 8 2026 flockfile(3)