degesch: further decoupling from Readline

degesch.c

@@ -57,6 +57,11 @@ enum
 #include <pwd.h>
 #include <sys/utsname.h>
 
+#include <termios.h>
+#ifndef TIOCGWINSZ
+#include <sys/ioctl.h>
+#endif  // ! TIOCGWINSZ
+
 #include <curses.h>
 #include <term.h>
 
@@ -777,9 +782,6 @@ struct app_context
 	iconv_t term_from_utf8;             ///< UTF-8 to terminal encoding
 	iconv_t latin1_to_utf8;             ///< ISO Latin 1 to UTF-8
 
-	int lines;                          ///< Current terminal height
-	int columns;                        ///< Current ternimal width
-
 	struct input input;                 ///< User interface
 }
 *g_ctx;
@@ -1128,9 +1130,33 @@ static struct
 
 	char *color_set_fg[8];              ///< Codes to set the foreground colour
 	char *color_set_bg[8];              ///< Codes to set the background colour
+
+	int lines;                          ///< Number of lines
+	int columns;                        ///< Number of columns
 }
 g_terminal;
 
+static void
+update_screen_size (void)
+{
+#ifdef TIOCGWINSZ
+	if (!g_terminal.stdout_is_tty)
+		return;
+
+	struct winsize size;
+	if (!ioctl (STDOUT_FILENO, TIOCGWINSZ, (char *) &size))
+	{
+		char *row = getenv ("LINES");
+		char *col = getenv ("COLUMNS");
+		unsigned long tmp;
+		g_terminal.lines =
+			(row && xstrtoul (&tmp, row, 10)) ? tmp : size.ws_row;
+		g_terminal.columns =
+			(col && xstrtoul (&tmp, col, 10)) ? tmp : size.ws_col;
+	}
+#endif // TIOCGWINSZ
+}
+
 static bool
 init_terminal (void)
 {
@@ -1152,6 +1178,10 @@ init_terminal (void)
 		return false;
 	}
 
+	g_terminal.lines   = tigetnum ("lines");
+	g_terminal.columns = tigetnum ("cols");
+	update_screen_size ();
+
 	for (size_t i = 0; i < N_ELEMENTS (g_terminal.color_set_fg); i++)
 	{
 		g_terminal.color_set_fg[i] = xstrdup (tparm (set_a_foreground,
@@ -1261,7 +1291,6 @@ init_colors (struct app_context *ctx)
 {
 	bool have_ti = init_terminal ();
 
-	// Use escape sequences from terminfo if possible, and SGR as a fallback
 #define INIT_ATTR(id, ti) init_attribute (ctx, ATTR_ ## id, have_ti ? (ti) : "")
 
 	INIT_ATTR (PROMPT,    enter_bold_mode);
@@ -1907,7 +1936,7 @@ buffer_activate (struct app_context *ctx, struct buffer *buffer)
 	print_status ("%s", buffer->name);
 
 	// That is, minus the buffer switch line and the readline prompt
-	int to_display = MAX (10, ctx->lines - 2);
+	int to_display = MAX (10, g_terminal.lines - 2);
 	struct buffer_line *line = buffer->lines_tail;
 	while (line && line->prev && --to_display > 0)
 		line = line->prev;
@@ -4858,7 +4887,7 @@ on_signal_pipe_readable (const struct pollfd *fd, struct app_context *ctx)
 	if (g_winch_received)
 	{
 		input_on_terminal_resized (&ctx->input);
-		rl_get_screen_size (&ctx->lines, &ctx->columns);
+		update_screen_size ();
 	}
 }
 
@@ -5081,7 +5110,6 @@ main (int argc, char *argv[])
 
 	refresh_prompt (&ctx);
 	input_start (&ctx.input);
-	rl_get_screen_size (&ctx.lines, &ctx.columns);
 
 	// Connect to the server ASAP
 	poller_timer_set (&ctx.server.reconnect_tmr, 0);