text: #include	"unp.h"
  
  void
  tv_sub(struct timeval *out, struct timeval *in)
  {
  	if ( (out->tv_usec -= in->tv_usec) < 0) {	/* out -= in */
  		--out->tv_sec;
  		out->tv_usec += 1000000;
  	}
  	out->tv_sec -= in->tv_sec;
  }
  