Index: head/usr.bin/uniq/uniq.1
===================================================================
--- head/usr.bin/uniq/uniq.1
+++ head/usr.bin/uniq/uniq.1
@@ -31,7 +31,7 @@
 .\"     From: @(#)uniq.1	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd December 17, 2009
+.Dd May 15, 2017
 .Dt UNIQ 1
 .Os
 .Sh NAME
@@ -39,7 +39,8 @@
 .Nd report or filter out repeated lines in a file
 .Sh SYNOPSIS
 .Nm
-.Op Fl c | Fl d | Fl u
+.Op Fl c
+.Op Fl d | Fl u
 .Op Fl i
 .Op Fl f Ar num
 .Op Fl s Ar chars
Index: head/usr.bin/uniq/uniq.c
===================================================================
--- head/usr.bin/uniq/uniq.c
+++ head/usr.bin/uniq/uniq.c
@@ -129,13 +129,6 @@
 	argc -= optind;
 	argv += optind;
 
-	/* If no flags are set, default is -d -u. */
-	if (cflag) {
-		if (dflag || uflag)
-			usage();
-	} else if (!dflag && !uflag)
-		dflag = uflag = 1;
-
 	if (argc > 2)
 		usage();
 
@@ -182,9 +175,6 @@
 	}
 	tprev = convert(prevline);
 
-	if (!cflag && uflag && dflag)
-		show(ofp, prevline);
-
 	tthis = NULL;
 	while (getline(&thisline, &thisbuflen, ifp) >= 0) {
 		if (tthis != NULL)
@@ -200,8 +190,7 @@
 
 		if (comp) {
 			/* If different, print; set previous to new value. */
-			if (cflag || !dflag || !uflag)
-				show(ofp, prevline);
+			show(ofp, prevline);
 			p = prevline;
 			b1 = prevbuflen;
 			prevline = thisline;
@@ -209,8 +198,6 @@
 			if (tprev != NULL)
 				free(tprev);
 			tprev = tthis;
-			if (!cflag && uflag && dflag)
-				show(ofp, prevline);
 			thisline = p;
 			thisbuflen = b1;
 			tthis = NULL;
@@ -220,8 +207,7 @@
 	}
 	if (ferror(ifp))
 		err(1, "%s", ifn);
-	if (cflag || !dflag || !uflag)
-		show(ofp, prevline);
+	show(ofp, prevline);
 	exit(0);
 }
 
@@ -286,9 +272,11 @@
 show(FILE *ofp, const char *str)
 {
 
+	if ((dflag && repeats == 0) || (uflag && repeats > 0))
+		return;
 	if (cflag)
 		(void)fprintf(ofp, "%4d %s", repeats + 1, str);
-	if ((dflag && repeats) || (uflag && !repeats))
+	else
 		(void)fprintf(ofp, "%s", str);
 }
 
@@ -351,6 +339,6 @@
 usage(void)
 {
 	(void)fprintf(stderr,
-"usage: uniq [-c | -d | -u] [-i] [-f fields] [-s chars] [input [output]]\n");
+"usage: uniq [-c] [-d | -u] [-i] [-f fields] [-s chars] [input [output]]\n");
 	exit(1);
 }