ls: Improve POSIX compatibility for -g and -n.

- Change -g (ignored for BSD 4.3 compatibility since BSD 4.4)
  to use POSIX semantics of implying -l but omitting the owner's
  name.

- Change -n to imply -l.

The -o option remains unchanged (POSIX defines -o as a complement to
-g that implies -l but omits group names whereas BSD defines -o to add
file flags to -l).  This compromise is the same used by both NetBSD
and OpenBSD.

PR:		70813
Reviewed by:	jhb, Pau Amma <pauamma@gundo.com>
Co-authored-by:	John Baldwin <jhb@FreeBSD.org>
Differential Revision:	https://reviews.freebsd.org/D34747

5 files changed, 28 insertions, 21 deletions

diff --git a/bin/ls/ls.1 b/bin/ls/ls.1
index fb1b4f6ba606..b3563eb38921 100644
--- a/bin/ls/ls.1
+++ b/bin/ls/ls.1
@@ -32,7 +32,7 @@
 .\"     @(#)ls.1	8.7 (Berkeley) 7/29/94
 .\" $FreeBSD$
 .\"
-.Dd October 31, 2022
+.Dd July 18, 2023
 .Dt LS 1
 .Os
 .Sh NAME
@@ -301,14 +301,9 @@ and
 .Fl s
 options.
 .It Fl g
-This option has no effect.
-It is only available for compatibility with
-.Bx 4.3 ,
-where it was used to display the group name in the long
+Display the long
 .Pq Fl l
-format output.
-This option is incompatible with
-.St -p1003.1-2008 .
+format output without the file owner's name or number.
 .It Fl h
 When used with the
 .Fl l
diff --git a/bin/ls/ls.c b/bin/ls/ls.c
index bd7bd283c317..b027e34afc2c 100644
--- a/bin/ls/ls.c
+++ b/bin/ls/ls.c
@@ -144,6 +144,7 @@ static int f_singlecol;		/* use single column output */
 static int f_sizesort;
        int f_slash;		/* similar to f_type, but only for dirs */
        int f_sortacross;	/* sort across rows, not down columns */
+       int f_sowner;		/* disable showing owner's name */
        int f_statustime;	/* use time of last mode change */
 static int f_stream;		/* stream the output, separate with commas */
        int f_thousands;		/* show file sizes with thousands separators */
@@ -402,7 +403,11 @@ main(int argc, char *argv[])
 			f_listdir = 1;
 			f_recursive = 0;
 			break;
-		case 'g':	/* Compatibility with 4.3BSD. */
+		case 'g':
+			f_longform = 1;
+			f_singlecol = 0;
+			f_stream = 0;
+			f_sowner = 1;
 			break;
 		case 'h':
 			f_humanval = 1;
@@ -421,6 +426,9 @@ main(int argc, char *argv[])
 			break;
 		case 'n':
 			f_numericonly = 1;
+			f_longform = 1;
+			f_singlecol = 0;
+			f_stream = 0;
 			break;
 		case 'o':
 			f_flags = 1;
diff --git a/bin/ls/ls.h b/bin/ls/ls.h
index 410246ec9903..1f19858720bf 100644
--- a/bin/ls/ls.h
+++ b/bin/ls/ls.h
@@ -56,6 +56,7 @@ extern int f_sectime;		/* print the real time for all files */
 extern int f_size;		/* list size in short listing */
 extern int f_slash;		/* append a '/' if the file is a directory */
 extern int f_sortacross;	/* sort across rows, not down columns */
+extern int f_sowner;		/* disable showing the owner's name */
 extern int f_statustime;	/* use time of last mode change */
 extern int f_thousands;		/* show file sizes with thousands separators */
 extern char *f_timeformat;	/* user-specified time format */
diff --git a/bin/ls/print.c b/bin/ls/print.c
index 5e8a54ca0620..b01b2e1e61db 100644
--- a/bin/ls/print.c
+++ b/bin/ls/print.c
@@ -234,9 +234,11 @@ printlong(const DISPLAY *dp)
 		strmode(sp->st_mode, buf);
 		aclmode(buf, p);
 		np = p->fts_pointer;
-		(void)printf("%s %*ju %-*s  %-*s  ", buf, dp->s_nlink,
-		    (uintmax_t)sp->st_nlink, dp->s_user, np->user, dp->s_group,
-		    np->group);
+		(void)printf("%s %*ju ", buf, dp->s_nlink,
+		    (uintmax_t)sp->st_nlink);
+		if (!f_sowner)
+			(void)printf("%-*s ", dp->s_user, np->user);
+		(void)printf("%-*s ", dp->s_group, np->group);
 		if (f_flags)
 			(void)printf("%-*s ", dp->s_flags, np->flags);
 		if (f_label)
diff --git a/bin/ls/tests/ls_tests.sh b/bin/ls/tests/ls_tests.sh
index 117156b5cb0e..a85e43ecb938 100755
--- a/bin/ls/tests/ls_tests.sh
+++ b/bin/ls/tests/ls_tests.sh
@@ -525,18 +525,19 @@ f_flag_body()
 atf_test_case g_flag
 g_flag_head()
 {
-	atf_set "descr" "Verify that -g does nothing (compatibility flag)"
+	atf_set "descr" "Verify that -g implies -l but omits the owner name field"
 }
 
 g_flag_body()
 {
-	create_test_inputs2
-	for file in $files; do
-		atf_check -e empty -o match:"$(ls -a $file)" -s exit:0 \
-		    ls -ag $file
-		atf_check -e empty -o match:"$(ls -la $file)" -s exit:0 \
-		    ls -alg $file
-	done
+	atf_check -e empty -o empty -s exit:0 touch a.file
+
+	mtime_in_secs=$(stat -f "%m" -t "%s" a.file)
+	mtime=$(date -j -f "%s" $mtime_in_secs +"%b[[:space:]]+%e[[:space:]]+%H:%M")
+
+	expected_output=$(stat -f "%Sp[[:space:]]+%l[[:space:]]+%Sg[[:space:]]+%z[[:space:]]+$mtime[[:space:]]+a\\.file" a.file)
+
+	atf_check -e empty -o match:"$expected_output" -s exit:0 ls -g a.file
 }
 
 atf_test_case h_flag
@@ -689,7 +690,7 @@ n_flag_body()
 
 	atf_check -e empty \
 	    -o match:'\-rw\-r\-\-r\-\-[[:space:]]+1[[:space:]]+'"$nobody_uid[[:space:]]+$daemon_gid"'[[:space:]]+.+a\.file' \
-	    ls -ln a.file
+	    ls -n a.file
 
 }