FFS (man3p)
ffs — find first set bit
ffs — find first set bit
l64a — convert a 32-bit integer to a radix-64 ASCII string
erfc, erfcf, erfcl — complementary error functions
sem_post — unlock a semaphore
strxfrm, strxfrm_l — string transformation
imaxabs — return absolute value
connect — connect a socket
utime — set file access and modification times
sched_getparam — get scheduling parameters (REALTIME)
wcslen, wcsnlen — get length of a fixed-sized wide-character string