text: /* /usr/lib/calendar produces an egrep -f file
     that will select today's and tomorrow's
     calendar entries, with special weekend provisions
  
     used by calendar command
  */
  #include <time.h>
  
  #define DAY (3600*24L)
  
  char *month[] = {
  	"[Jj]an",
  	"[Ff]eb",
  	"[Mm]ar",
  	"[Aa]pr",
  	"[Mm]ay",
  	"[Jj]un",
  	"[Jj]ul",
  	"[Aa]ug",
  	"[Ss]ep",
  	"[Oo]ct",
  	"[Nn]ov",
  	"[Dd]ec"
  };
  struct tm *localtime();
  
  tprint(t)
  long t;
  {
  	struct tm *tm;
  	tm = localtime(&t);
  	printf("(^|[ (,;])((%s[^ ]* *|%d/)0*%d)([^0123456789]|$)\n",
  		month[tm->tm_mon], tm->tm_mon + 1, tm->tm_mday);
  }
  
  main()
  {
  	long t;
  	time(&t);
  	tprint(t);
  	switch(localtime(&t)->tm_wday) {
  	case 5:
  		t += DAY;
  		tprint(t);
  	case 6:
  		t += DAY;
  		tprint(t);
  	default:
  		t += DAY;
  		tprint(t);
  	}
  }
  