From beff530ff56c9536e56f78df4fd679dce56a05fb Mon Sep 17 00:00:00 2001
From: Ian Lepore <ian@FreeBSD.org>
Date: Sun, 22 Dec 2019 20:34:15 +0000
Subject: [PATCH] MFC r355777:

Support --all-repeats in uniq(1) for compatibility with gnu coreutils.

This adds a new -D/--all-repeats option to uniq(1), which outputs each copy
of any repeated lines (as opposed to a single copy of a repeated line). You
can specify a separator option to output a blank line before or after each
group of repeated lines. This adds compatibility with the GNU coreutils
version of uniq(1).

This change also re-groups the -c, -d, -D, -u options in the usage display
and man page to indicate that they are mutally exclusive of each other. This
matches the posix/opengroup definition of uniq(1) command line args. Note
that this change does NOT actually enforce the mutual exclusion in the code,
for now, it simply documents that the arguments should be considered
exclusive with each other.

Differential Revision:	https://reviews.freebsd.org/D22262
---
 usr.bin/uniq/uniq.1 | 24 ++++++++++++++++++++----
 usr.bin/uniq/uniq.c | 44 +++++++++++++++++++++++++++++++++++++-------
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/usr.bin/uniq/uniq.1 b/usr.bin/uniq/uniq.1
index 9fa37ef8b8e..bcb6d4508f9 100644
--- a/usr.bin/uniq/uniq.1
+++ b/usr.bin/uniq/uniq.1
@@ -31,7 +31,7 @@
 .\"     From: @(#)uniq.1	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd May 1, 2018
+.Dd December 15, 2019
 .Dt UNIQ 1
 .Os
 .Sh NAME
@@ -39,8 +39,7 @@
 .Nd report or filter out repeated lines in a file
 .Sh SYNOPSIS
 .Nm
-.Op Fl c
-.Op Fl d | Fl u
+.Op Fl c | Fl d | Fl D | Fl u
 .Op Fl i
 .Op Fl f Ar num
 .Op Fl s Ar chars
@@ -75,7 +74,24 @@ The following options are available:
 Precede each output line with the count of the number of times the line
 occurred in the input, followed by a single space.
 .It Fl d , Fl -repeated
-Only output lines that are repeated in the input.
+Output a single copy of each line that is repeated in the input.
+.It Fl D , Fl -all-repeated Op Ar septype
+Output all lines that are repeated (like
+.Fl d ,
+but each copy of the repeated line is written).
+The optional
+.Ar septype
+argument controls how to separate groups of repeated lines in the output;
+it must be one of the following values:
+.Pp
+.Bl -tag -compact -width separate
+.It none
+Do not separate groups of lines (this is the default).
+.It prepend
+Output an empty line before each group of lines.
+.It separate
+Output an empty line after each group of lines.
+.El
 .It Fl f Ar num , Fl -skip-fields Ar num
 Ignore the first
 .Ar num
diff --git a/usr.bin/uniq/uniq.c b/usr.bin/uniq/uniq.c
index dce2bbd82ab..5d2a7c1f224 100644
--- a/usr.bin/uniq/uniq.c
+++ b/usr.bin/uniq/uniq.c
@@ -65,11 +65,18 @@ static const char rcsid[] =
 #include <wchar.h>
 #include <wctype.h>
 
-static int cflag, dflag, uflag, iflag;
+static int Dflag, cflag, dflag, uflag, iflag;
 static int numchars, numfields, repeats;
 
+/* Dflag values */
+#define	DF_NONE		0
+#define	DF_NOSEP	1
+#define	DF_PRESEP	2
+#define	DF_POSTSEP	3
+
 static const struct option long_opts[] =
 {
+	{"all-repeated",optional_argument,	NULL, 'D'},
 	{"count",	no_argument,		NULL, 'c'},
 	{"repeated",	no_argument,		NULL, 'd'},
 	{"skip-fields",	required_argument,	NULL, 'f'},
@@ -101,9 +108,19 @@ main (int argc, char *argv[])
 	(void) setlocale(LC_ALL, "");
 
 	obsolete(argv);
-	while ((ch = getopt_long(argc, argv, "+cdif:s:u", long_opts,
+	while ((ch = getopt_long(argc, argv, "+D::cdif:s:u", long_opts,
 	    NULL)) != -1)
 		switch (ch) {
+		case 'D':
+			if (optarg == NULL || strcasecmp(optarg, "none") == 0)
+				Dflag = DF_NOSEP;
+			else if (strcasecmp(optarg, "prepend") == 0)
+				Dflag = DF_PRESEP;
+			else if (strcasecmp(optarg, "separate") == 0)
+				Dflag = DF_POSTSEP;
+			else
+				usage();
+			break;
 		case 'c':
 			cflag = 1;
 			break;
@@ -194,7 +211,10 @@ main (int argc, char *argv[])
 
 		if (comp) {
 			/* If different, print; set previous to new value. */
-			show(ofp, prevline);
+			if (Dflag == DF_POSTSEP && repeats > 0)
+				fputc('\n', ofp);
+			if (!Dflag)
+				show(ofp, prevline);
 			p = prevline;
 			b1 = prevbuflen;
 			prevline = thisline;
@@ -206,12 +226,22 @@ main (int argc, char *argv[])
 			thisbuflen = b1;
 			tthis = NULL;
 			repeats = 0;
-		} else
+		} else {
+			if (Dflag) {
+				if (repeats == 0) {
+					if (Dflag == DF_PRESEP)
+						fputc('\n', ofp);
+					show(ofp, prevline);
+				}
+				show(ofp, thisline);
+			}
 			++repeats;
+		}
 	}
 	if (ferror(ifp))
 		err(1, "%s", ifn);
-	show(ofp, prevline);
+	if (!Dflag)
+		show(ofp, prevline);
 	exit(0);
 }
 
@@ -276,7 +306,7 @@ static void
 show(FILE *ofp, const char *str)
 {
 
-	if ((dflag && repeats == 0) || (uflag && repeats > 0))
+	if ((!Dflag && dflag && repeats == 0) || (uflag && repeats > 0))
 		return;
 	if (cflag)
 		(void)fprintf(ofp, "%4d %s", repeats + 1, str);
@@ -343,6 +373,6 @@ static void
 usage(void)
 {
 	(void)fprintf(stderr,
-"usage: uniq [-c] [-d | -u] [-i] [-f fields] [-s chars] [input [output]]\n");
+"usage: uniq [-c | -d | -D | -u] [-i] [-f fields] [-s chars] [input [output]]\n");
 	exit(1);
 }
-- 
2.45.0