ualarm(3) Library Functions Manual ualarm(3) ualarm - (libc -lc) #include useconds_t ualarm(useconds_t usecs, useconds_t interval); glibc ( feature_test_macros(7)): ualarm(): glibc 2.12: (_XOPEN_SOURCE >= 500) && ! (_POSIX_C_SOURCE >= 200809L) || /* glibc >= 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE glibc 2.12: _BSD_SOURCE || _XOPEN_SOURCE >= 500 ualarm() SIGALRM ( ) usecs . . SIGALRM . interval SIGALRM interval . 0 . EINTR signal(7). EINVAL usecs interval 1000000. ( .) attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |ualarm() | | MT-Safe | +------------+------------------------------------+--------------------+ . 4.3BSD POSIX.1-2001. POSIX.1-2001 . POSIX.1-2008. 4.3BSD SUSv2 POSIX . POSIX.1-2001 usecs 0. ( ) . useconds_t [0,1000000]. BSD glibc glibc 2.1 ualarm() unsigned int. useconds_t . alarm(2) sleep(3) nanosleep(2) setitimer(2) timer_create(2) timer_delete(2) timer_getoverrun(2) timer_gettime(2) timer_settime(2) usleep(3) . . setitimer(2) POSIX (timer_create(2) ) . alarm(2) getitimer(2) nanosleep(2) select(2) setitimer(2) usleep(3) time(7) 3 . . : . 6.18 8 2026 ualarm(3)