Make libncurses catch SIGWINCH and update the values for LINES and COLS.

I was perplexed when an example I'd written to show the values for these
variables changing as an xterm window was resized didn't work, and looking
into it I see that size tracking for LINES and COLS seems to be one SVR4
enhancement which didn't come across with libncurses.

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/libncurses/lib_newterm.c b/lib/libncurses/lib_newterm.c
index 79e5b4e..d72946e 100644
--- a/lib/libncurses/lib_newterm.c
+++ b/lib/libncurses/lib_newterm.c
@@ -31,6 +31,17 @@ static void cleanup(int sig)
 	exit(1);
 }
 
+static void
+size_change(int sig)
+{
+	struct ttysize ws;
+
+	if (ioctl(0, TIOCGSIZE, &ws) == -1)
+		return;
+	LINES = ws.ts_lines;
+	COLS = ws.ts_cols;
+}
+
 WINDOW *stdscr, *curscr, *newscr;
 SCREEN *SP;
 
@@ -130,6 +141,10 @@ char   *use_it = _ncurses_copyright;
 	act.sa_flags = 0;
 	sigaction(SIGINT, &act, NULL);
 	sigaction(SIGTERM, &act, NULL);
+	act.sa_handler = size_change;
+	sigemptyset(&act.sa_mask);
+	act.sa_flags = 0;
+	sigaction(SIGWINCH, &act, NULL);
 #if 0
 	sigaction(SIGSEGV, &act, NULL);
 #endif