USLEEP

usleep ? suspend execution for interval of microseconds

#include <unistd.h>

void usleep(unsigned long usec);

The usleep() function suspends execution of the calling process for usec microseconds. The sleep may be lengthened slightly by any system activity or by the time spent processing the call.

BSD 4.3

setitimer(2), getitimer(2), sleep(3), alarm(2), select(2)