2 files changed, 26 insertions, 3 deletions

diff --git a/bin/chflags/chflags.1 b/bin/chflags/chflags.1
index 6966f6c0fbc4..942cfe9bf137 100644
--- a/bin/chflags/chflags.1
+++ b/bin/chflags/chflags.1
@@ -32,7 +32,7 @@
 .\"	@(#)chflags.1	8.4 (Berkeley) 5/2/95
 .\" $FreeBSD$
 .\"
-.Dd March 4, 2018
+.Dd March 6, 2018
 .Dt CHFLAGS 1
 .Os
 .Sh NAME
@@ -217,6 +217,16 @@ setting.
 See
 .Xr security 7
 for more information on this setting.
+.Pp
+If
+.Nm
+receives a
+.Dv SIGINFO
+signal (see the
+.Cm status
+argument for
+.Xr stty 1 ) ,
+then the current filename as well as the old and new flags are displayed.
 .Sh EXIT STATUS
 .Ex -std
 .Sh SEE ALSO
diff --git a/bin/chflags/chflags.c b/bin/chflags/chflags.c
index 3121f470e13a..c1d9c18b9b6b 100644
--- a/bin/chflags/chflags.c
+++ b/bin/chflags/chflags.c
@@ -51,13 +51,23 @@ __FBSDID("$FreeBSD$");
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
+static volatile sig_atomic_t siginfo;
+
 static void usage(void);
 
+static void
+siginfo_handler(int sig __unused)
+{
+
+	siginfo = 1;
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -108,6 +118,8 @@ main(int argc, char *argv[])
 	if (argc < 2)
 		usage();
 
+	(void)signal(SIGINFO, siginfo_handler);
+
 	if (Rflag) {
 		if (hflag)
 			errx(1, "the -R and -h options may not be "
@@ -188,13 +200,14 @@ main(int argc, char *argv[])
 		    atflag) == -1 && !fflag) {
 			warn("%s", p->fts_path);
 			rval = 1;
-		} else if (vflag) {
+		} else if (vflag || siginfo) {
 			(void)printf("%s", p->fts_path);
-			if (vflag > 1)
+			if (vflag > 1 || siginfo)
 				(void)printf(": 0%lo -> 0%lo",
 				    (u_long)p->fts_statp->st_flags,
 				    newflags);
 			(void)printf("\n");
+			siginfo = 0;
 		}
 	}
 	if (errno)