systat: Handle SIGWINCH to properly window resizing and adjust

-swap disk stat based on new size.

Display corrupts after resizing a window.
Process SIGWINCH to redraw all window.

Submitted by:   Yoshihiro Ota ota@j.email.ne.jp
Differential Revision:  https://reviews.freebsd.org/D29337

4 files changed, 22 insertions, 10 deletions

diff --git a/usr.bin/systat/devs.c b/usr.bin/systat/devs.c
index b293796c2c77..87d04f989ea3 100644
--- a/usr.bin/systat/devs.c
+++ b/usr.bin/systat/devs.c
@@ -426,12 +426,6 @@ dsshow2(int diskcol, int diskrow, int dn, int lc, struct statinfo *now, struct s
 	putlongdouble(device_busy, diskrow + 4, lc, 5, 0, 0);
 }
 
-static void
-dsshow3(int diskcol, int diskrow, int dn, int lc, struct statinfo *now, struct statinfo *then)
-{
-	dsshow2(diskcol, diskrow, dn, lc, now, then);
-}
-
 void
 dsshow(int maxdrives, int diskcol, int diskrow, struct statinfo *now, struct statinfo *then)
 {
@@ -439,5 +433,5 @@ dsshow(int maxdrives, int diskcol, int diskrow, struct statinfo *now, struct sta
 
 	for (i = 0, lc = 0; i < num_devices && lc < maxdrives; i++)
 		if (dev_select[i].selected)
-			dsshow3(diskcol, diskrow, i, ++lc, now, then);
+			dsshow2(diskcol, diskrow, i, ++lc, now, then);
 }
diff --git a/usr.bin/systat/devs.h b/usr.bin/systat/devs.h
index cbedd844290e..79a44a6c3f5e 100644
--- a/usr.bin/systat/devs.h
+++ b/usr.bin/systat/devs.h
@@ -2,7 +2,7 @@
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 1998 David E. O'Brien
- *               2015 Yoshihiro Ota
+ *               2015, 2021 Yoshihiro Ota
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,6 +34,8 @@
 
 #include <devstat.h>
 
+#define DISKHIGHT 5
+
 int dsinit(int);
 void dsgetinfo(struct statinfo *);
 int dscmd(const char *, const char *, int, struct statinfo *);
diff --git a/usr.bin/systat/main.c b/usr.bin/systat/main.c
index b5a19d381ada..b84351379f41 100644
--- a/usr.bin/systat/main.c
+++ b/usr.bin/systat/main.c
@@ -135,6 +135,21 @@ parse_cmd_args (int argc, char **argv)
 
 }
 
+static void
+resize(int signo __unused)
+{
+
+	endwin();
+	refresh();
+	clear();
+
+	CMDLINE = LINES - 1;
+	labels();
+	display();
+	status();
+}
+
+
 int
 main(int argc, char **argv)
 {
@@ -191,6 +206,7 @@ main(int argc, char **argv)
 	signal(SIGINT, die);
 	signal(SIGQUIT, die);
 	signal(SIGTERM, die);
+	signal(SIGWINCH, resize);
 
 	/*
 	 * Initialize display.  Load average appears in a one line
diff --git a/usr.bin/systat/swap.c b/usr.bin/systat/swap.c
index 29b04df0157f..6052ca0d877b 100644
--- a/usr.bin/systat/swap.c
+++ b/usr.bin/systat/swap.c
@@ -136,7 +136,7 @@ labelswap(void)
 
 	werase(wnd);
 
-	dslabel(12, 0, 18);
+	dslabel(12, 0, LINES - DISKHIGHT - 1);
 
 	if (kvnsw <= 0) {
 		mvwprintw(wnd, 0, 0, "(swap not configured)");
@@ -162,7 +162,7 @@ showswap(void)
 	if (kvnsw != okvnsw)
 		labelswap();
 
-	dsshow(12, 0, 18, &cur_dev, &last_dev);
+	dsshow(12, 0, LINES - DISKHIGHT - 1, &cur_dev, &last_dev);
 
 	if (kvnsw <= 0)
 		return;