cmp: add -b, --print-bytes

This is compatible with GNU cmp.

Reviewed by:	bapt, markj (earlier version)
Sponsored by:	Klara, Inc.

(cherry picked from commit f66b9b40f403f7c30fec3c4ceed93c6e8fafa8ac)

11 files changed, 70 insertions, 16 deletions

diff --git a/usr.bin/cmp/cmp.1 b/usr.bin/cmp/cmp.1
index 5a56802bd22e..3e616bbe806e 100644
--- a/usr.bin/cmp/cmp.1
+++ b/usr.bin/cmp/cmp.1
@@ -40,7 +40,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl l | s | x
-.Op Fl hz
+.Op Fl bhz
 .Op Fl -ignore-initial Ns Cm = Ns Ar num1 Ns Op :num2
 .Op Fl -bytes Ns Cm = Ns Ar num
 .Ar file1 file2
@@ -59,6 +59,8 @@ Bytes and lines are numbered beginning with one.
 .Pp
 The following options are available:
 .Bl -tag -width indent
+.It Fl b , Fl -print-bytes
+Print each byte when a difference is found.
 .It Fl h
 Do not follow symbolic links.
 .It Fl i Ar num1 Ns Oo :num2 Oc , Fl -ignore-initial= Ns Ar num1 Ns Op :num2
@@ -187,6 +189,7 @@ utility is expected to be
 .St -p1003.2
 compatible.
 The
+.Fl b ,
 .Fl h ,
 .Fl i ,
 .Fl n ,
diff --git a/usr.bin/cmp/cmp.c b/usr.bin/cmp/cmp.c
index 256cef8a0c31..98ae96c73375 100644
--- a/usr.bin/cmp/cmp.c
+++ b/usr.bin/cmp/cmp.c
@@ -62,10 +62,11 @@ __FBSDID("$FreeBSD$");
 
 #include "extern.h"
 
-bool	lflag, sflag, xflag, zflag;
+bool	bflag, lflag, sflag, xflag, zflag;
 
 static const struct option long_opts[] =
 {
+	{"print-bytes",	no_argument,		NULL, 'b'},
 	{"ignore-initial", required_argument,	NULL, 'i'},
 	{"verbose",	no_argument,		NULL, 'l'},
 	{"bytes",	required_argument,	NULL, 'n'},
@@ -106,8 +107,11 @@ main(int argc, char *argv[])
 
 	skip1 = skip2 = 0;
 	oflag = O_RDONLY;
-	while ((ch = getopt_long(argc, argv, "+hi:ln:sxz", long_opts, NULL)) != -1)
+	while ((ch = getopt_long(argc, argv, "+bhi:ln:sxz", long_opts, NULL)) != -1)
 		switch (ch) {
+		case 'b':		/* Print bytes */
+			bflag = true;
+			break;
 		case 'h':		/* Don't follow symlinks */
 			oflag |= O_NOFOLLOW;
 			break;
diff --git a/usr.bin/cmp/extern.h b/usr.bin/cmp/extern.h
index 803319a50ca4..d98daf424995 100644
--- a/usr.bin/cmp/extern.h
+++ b/usr.bin/cmp/extern.h
@@ -42,7 +42,7 @@ void	c_link(const char *, off_t, const char *, off_t, off_t);
 void	c_regular(int, const char *, off_t, off_t, int, const char *, off_t,
 	    off_t, off_t);
 void	c_special(int, const char *, off_t, int, const char *, off_t, off_t);
-void	diffmsg(const char *, const char *, off_t, off_t);
+void	diffmsg(const char *, const char *, off_t, off_t, int, int);
 void	eofmsg(const char *);
 
-extern bool lflag, sflag, xflag, zflag;
+extern bool bflag, lflag, sflag, xflag, zflag;
diff --git a/usr.bin/cmp/link.c b/usr.bin/cmp/link.c
index f0b4482a5792..e01a5911faf7 100644
--- a/usr.bin/cmp/link.c
+++ b/usr.bin/cmp/link.c
@@ -82,10 +82,14 @@ c_link(const char *file1, off_t skip1, const char *file2, off_t skip2,
 				    (long long)byte - 1, ch, *p2);
 			} else if (lflag) {
 				dfound = 1;
-				(void)printf("%6lld %3o %3o\n",
-				    (long long)byte, ch, *p2);
+				if (bflag)
+					(void)printf("%6lld %3o %c %3o %c\n",
+					    (long long)byte, ch, ch, *p2, *p2);
+				else
+					(void)printf("%6lld %3o %3o\n",
+					    (long long)byte, ch, *p2);
 			} else
-				diffmsg(file1, file2, byte, 1);
+				diffmsg(file1, file2, byte, 1, ch, *p2);
 				/* NOTREACHED */
 		}
 		byte++;
diff --git a/usr.bin/cmp/misc.c b/usr.bin/cmp/misc.c
index 1e84f0d7a527..1dba34d28792 100644
--- a/usr.bin/cmp/misc.c
+++ b/usr.bin/cmp/misc.c
@@ -56,10 +56,20 @@ eofmsg(const char *file)
 }
 
 void
-diffmsg(const char *file1, const char *file2, off_t byte, off_t line)
+diffmsg(const char *file1, const char *file2, off_t byte, off_t line,
+    int b1, int b2)
 {
-	if (!sflag)
+	if (sflag)
+		goto out;
+
+	if (bflag) {
+		(void)printf("%s %s differ: char %lld, line %lld is %3o %c %3o %c\n",
+		    file1, file2, (long long)byte, (long long)line, b1, b1,
+		    b2, b2);
+	} else {
 		(void)printf("%s %s differ: char %lld, line %lld\n",
 		    file1, file2, (long long)byte, (long long)line);
+	}
+out:
 	exit(DIFF_EXIT);
 }
diff --git a/usr.bin/cmp/regular.c b/usr.bin/cmp/regular.c
index a60398620282..d270aeeac396 100644
--- a/usr.bin/cmp/regular.c
+++ b/usr.bin/cmp/regular.c
@@ -127,10 +127,14 @@ c_regular(int fd1, const char *file1, off_t skip1, off_t len1,
 				    (long long)byte - 1, ch, *p2);
 			} else if (lflag) {
 				dfound = 1;
-				(void)printf("%6lld %3o %3o\n",
-				    (long long)byte, ch, *p2);
+				if (bflag)
+					(void)printf("%6lld %3o %c %3o %c\n",
+					    (long long)byte, ch, ch, *p2, *p2);
+				else
+					(void)printf("%6lld %3o %3o\n",
+					    (long long)byte, ch, *p2);
 			} else
-				diffmsg(file1, file2, byte, line);
+				diffmsg(file1, file2, byte, line, ch, *p2);
 				/* NOTREACHED */
 		}
 		if (ch == '\n')
diff --git a/usr.bin/cmp/special.c b/usr.bin/cmp/special.c
index 25f755f6e70a..c206a317c0ef 100644
--- a/usr.bin/cmp/special.c
+++ b/usr.bin/cmp/special.c
@@ -88,10 +88,15 @@ c_special(int fd1, const char *file1, off_t skip1,
 				    (long long)byte - 1, ch1, ch2);
 			} else if (lflag) {
 				dfound = 1;
-				(void)printf("%6lld %3o %3o\n",
-				    (long long)byte, ch1, ch2);
+				if (bflag)
+					(void)printf("%6lld %3o %c %3o %c\n",
+					    (long long)byte, ch1, ch1, ch2,
+					    ch2);
+				else
+					(void)printf("%6lld %3o %3o\n",
+					    (long long)byte, ch1, ch2);
 			} else {
-				diffmsg(file1, file2, byte, line);
+				diffmsg(file1, file2, byte, line, ch1, ch2);
 				/* NOTREACHED */
 			}
 		}
diff --git a/usr.bin/cmp/tests/Makefile b/usr.bin/cmp/tests/Makefile
index 087f32f4185f..99469ba42243 100644
--- a/usr.bin/cmp/tests/Makefile
+++ b/usr.bin/cmp/tests/Makefile
@@ -2,9 +2,14 @@
 
 .include <bsd.own.mk>
 
+PACKAGE=	tests
+
 ATF_TESTS_SH+=		cmp_test2
 NETBSD_ATF_TESTS_SH=	cmp_test
 
+${PACKAGE}FILES+=	b_flag.out
+${PACKAGE}FILES+=	bl_flag.out
+
 .include <netbsd-tests.test.mk>
 
 .include <bsd.test.mk>
diff --git a/usr.bin/cmp/tests/b_flag.out b/usr.bin/cmp/tests/b_flag.out
new file mode 100644
index 000000000000..bb3d288716b0
--- /dev/null
+++ b/usr.bin/cmp/tests/b_flag.out
@@ -0,0 +1 @@
+a b differ: char 3, line 1 is 143 c 144 d
diff --git a/usr.bin/cmp/tests/bl_flag.out b/usr.bin/cmp/tests/bl_flag.out
new file mode 100644
index 000000000000..8ec9007d7ed3
--- /dev/null
+++ b/usr.bin/cmp/tests/bl_flag.out
@@ -0,0 +1 @@
+     3 143 c 144 d
diff --git a/usr.bin/cmp/tests/cmp_test2.sh b/usr.bin/cmp/tests/cmp_test2.sh
index 893ee59076c3..c264827646ca 100755
--- a/usr.bin/cmp/tests/cmp_test2.sh
+++ b/usr.bin/cmp/tests/cmp_test2.sh
@@ -118,6 +118,22 @@ limit_body()
 	atf_check -s exit:1 -o ignore -x "cat a | cmp -sn 5 b -"
 }
 
+atf_test_case bflag
+bflag_head()
+{
+	atf_set "descr" "Test cmp(1) -b (print bytes)"
+}
+bflag_body()
+{
+	echo -n "abcd" > a
+	echo -n "abdd" > b
+
+	atf_check -s exit:1 -o file:$(atf_get_srcdir)/b_flag.out \
+	    cmp -b a b
+	atf_check -s exit:1 -o file:$(atf_get_srcdir)/bl_flag.out \
+	    cmp -bl a b
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case special
@@ -125,4 +141,5 @@ atf_init_test_cases()
 	atf_add_test_case pr252542
 	atf_add_test_case skipsuff
 	atf_add_test_case limit
+	atf_add_test_case bflag
 }