Index: usr.bin/diff/diff.c
===================================================================
--- usr.bin/diff/diff.c
+++ usr.bin/diff/diff.c
@@ -322,7 +322,7 @@
 		if (S_ISDIR(stb2.st_mode)) {
 			argv[1] = splice(argv[1], argv[0]);
 			if (stat(argv[1], &stb2) < 0)
-				err(2, "%s", argv[1]);
+				warn(2, "%s", argv[1]);
 		}
 		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
 		    argv[1], "");
Index: usr.bin/env/env.1
===================================================================
--- usr.bin/env/env.1
+++ usr.bin/env/env.1
@@ -31,7 +31,7 @@
 .\" From FreeBSD: src/usr.bin/printenv/printenv.1,v 1.17 2002/11/26 17:33:35 ru Exp
 .\" $FreeBSD$
 .\"
-.Dd April 17, 2008
+.Dd November 3, 2019
 .Dt ENV 1
 .Os
 .Sh NAME
@@ -39,7 +39,7 @@
 .Nd set environment and execute command, or print environment
 .Sh SYNOPSIS
 .Nm
-.Op Fl iv
+.Op Fl 0iv
 .Op Fl P Ar altpath
 .Op Fl S Ar string
 .Op Fl u Ar name
@@ -64,6 +64,8 @@
 .Pp
 The options are as follows:
 .Bl -tag -width indent
+.It Fl 0
+End each output line with NUL, not newline.
 .It Fl i
 Execute the
 .Ar utility
@@ -132,6 +134,11 @@
 .Nm
 prints out the names and values
 of the variables in the environment, with one name/value pair per line.
+If
+.Fl 0
+is supplied,
+.Ar utility
+is ignored and the variables are separated by NUL instead of lines.
 .\"
 .Ss Details of Fl S \&Ss (split-string) processing
 The processing of the
Index: usr.bin/env/env.c
===================================================================
--- usr.bin/env/env.c
+++ usr.bin/env/env.c
@@ -62,19 +62,23 @@
 int
 main(int argc, char **argv)
 {
-	char *altpath, **ep, *p, **parg;
+	char *altpath, **ep, *p, **parg, term;
 	char *cleanenv[1];
 	int ch, want_clear;
 	int rtrn;
 
 	altpath = NULL;
 	want_clear = 0;
-	while ((ch = getopt(argc, argv, "-iP:S:u:v")) != -1)
+	term = '\n';
+	while ((ch = getopt(argc, argv, "-0iP:S:u:v")) != -1)
 		switch(ch) {
 		case '-':
 		case 'i':
 			want_clear = 1;
 			break;
+		case '0':
+			term = '\0';
+			break;
 		case 'P':
 			altpath = strdup(optarg);
 			break;
@@ -118,21 +122,25 @@
 			err(EXIT_FAILURE, "setenv %s", *argv);
 	}
 	if (*argv) {
-		if (altpath)
-			search_paths(altpath, argv);
-		if (env_verbosity) {
-			fprintf(stderr, "#env executing:\t%s\n", *argv);
-			for (parg = argv, argc = 0; *parg; parg++, argc++)
-				fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
-				    argc, *parg);
-			if (env_verbosity > 1)
-				sleep(1);
+		if (term == '\0')
+			fprintf(stderr, "Command ignored with -0.\n");
+		else {
+			if (altpath)
+				search_paths(altpath, argv);
+			if (env_verbosity) {
+				fprintf(stderr, "#env executing:\t%s\n", *argv);
+				for (parg = argv, argc = 0; *parg; parg++, argc++)
+					fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
+						argc, *parg);
+				if (env_verbosity > 1)
+					sleep(1);
+			}
+			execvp(*argv, argv);
+			err(errno == ENOENT ? 127 : 126, "%s", *argv);
 		}
-		execvp(*argv, argv);
-		err(errno == ENOENT ? 127 : 126, "%s", *argv);
 	}
 	for (ep = environ; *ep; ep++)
-		(void)printf("%s\n", *ep);
+		(void)printf("%s%c", *ep, term);
 	exit(0);
 }
 
@@ -140,7 +148,7 @@
 usage(void)
 {
 	(void)fprintf(stderr,
-	    "usage: env [-iv] [-P utilpath] [-S string] [-u name]\n"
+	    "usage: env [-0iv] [-P utilpath] [-S string] [-u name]\n"
 	    "           [name=value ...] [utility [argument ...]]\n");
 	exit(1);
 }