From 867de51629975db34b5745118fb283d126f476ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20Ankarstr=C3=B6m?= <john@ankarstrom.se>
Date: Fri, 6 Nov 2020 21:02:30 +0100
Subject: add prn macro

---
 l.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/l.c b/l.c
index 2248da6..c707aea 100644
--- a/l.c
+++ b/l.c
@@ -12,6 +12,8 @@
 #define ESC "\033"
 #define CSI ESC "["
 
+#define prn(...) dprintf(ttyfd, __VA_ARGS__)
+
 int ttyfd;
 
 /* enable/disable "raw" mode */
@@ -42,7 +44,7 @@ int cpr(int *x, int *y) {
 	char c, xbuf[4], ybuf[4];
 	int i;
 
-	write (1, CSI "6n", 2+2);
+	prn(CSI "6n");
 
 	/* get CSI */
 	read(1, &c, 1);
@@ -81,9 +83,12 @@ void left() {}
 
 int main() {
 	char c, *p;
-	char *ex = "file1 file2 file3\r\nfile4 file5 file6\r\nfile7";
-	int i, r, x, x2, y, y2;
+	int i, r;
 	struct winsize w;
+	int height; /* height of output in rows */
+	int x, y; /* original cursor position in cols, rows */
+
+	char *ex = "file1 file2 file3\r\nfile4 file5 file6\r\nfile7";
 
 	ttyfd = open("/dev/tty", O_RDWR);
 	if (ttyfd == -1) err(1, "open");
@@ -95,25 +100,25 @@ int main() {
 	if (r == -1) goto quit;
 
 	/* print output */
-	dprintf(ttyfd, "%s", ex);
+	prn("%s", ex);
 
 	/* get height of output */
 	p = ex - 1;
-	i = 0;
+	height = 0;
 	while (*(++p) != '\0')
-		if (*p == '\n') i++;
+		if (*p == '\n') height++;
 
 	/* get height of terminal */
 	r = ioctl(ttyfd, TIOCGWINSZ, &w);
 	if (r == -1) err(1, "ioctl");
 
 	/* correct cursor position if original cursor was near bottom */
-	r = y + i - w.ws_row;
+	r = y + height - w.ws_row;
 	if (r > 0)
 		y = y - r;
 
-	/* restore original cursor position */
-	dprintf(ttyfd, "%s%d;%dH", CSI, y, x); /* restore cursor position (CUP) */
+	/* restore original cursor position (CUP) */
+	prn("%s%d;%dH", CSI, y, x);
 
 	while (read(0, &c, 1) != 0) {
 		switch (c) {
@@ -133,5 +138,6 @@ int main() {
 	}
 	
 quit:
+	prn(CSI "J"); /* delete from cursor to end of display (ED) */
 	raw(false);
 }
-- 
cgit v1.2.3