[PATCH] term-utils: Make scriptreplay set terminal to raw mode

[Soumendra Ganguly <soumendraganguly@gmail.com>]

scriptreplay produces garbled output while replaying certain curses
sessions. script(1) from util-linux is able to record the sessions
correctly.

The following programs can be used to demonstrate this.

1. A curses-based game called "greed"; a Debian 10 package named
"greed" is available.

2. A Python implementation of Conway's game of life by GitHub user
iiSeymour. The repository is named game-of-life.

Expected output is obtained by making scriptreplay call cfmakeraw.

Signed-off-by: Soumendra Ganguly <soumendraganguly@gmail.com>
---
 term-utils/scriptreplay.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/term-utils/scriptreplay.c b/term-utils/scriptreplay.c
index bca1d21b4..19a7d568b 100644
--- a/term-utils/scriptreplay.c
+++ b/term-utils/scriptreplay.c
@@ -28,6 +28,7 @@
 #include <unistd.h>
 #include <getopt.h>
 #include <sys/time.h>
+#include <termios.h>

 #include "c.h"
 #include "xalloc.h"
@@ -120,12 +121,30 @@ static void appendchr(char *buf, size_t bufsz, int c)
 		buf[sz] = c;
 }

+static int termraw(struct termios *backup)
+{
+	struct termios tattr;
+
+	if (tcgetattr(STDOUT_FILENO, backup) != 0)
+		return -1;
+
+	tattr = *backup;
+	cfmakeraw(&tattr);
+	if (tcsetattr(STDOUT_FILENO, TCSANOW, &tattr) != 0)
+		return -1;
+
+	return 0;
+}
+
 int
 main(int argc, char *argv[])
 {
 	static const struct timeval mindelay = { .tv_sec = 0, .tv_usec = 100 };
 	struct timeval maxdelay;

+	char isterm;
+	struct termios saved;
+
 	struct replay_setup *setup = NULL;
 	struct replay_step *step = NULL;
 	char streams[6] = {0};		/* IOSI - in, out, signal,info */
@@ -286,6 +305,10 @@ main(int argc, char *argv[])
 		replay_set_delay_max(setup, &maxdelay);
 	replay_set_delay_min(setup, &mindelay);

+	isterm = isatty(STDOUT_FILENO);
+	if (isterm && termraw(&saved) != 0)
+		err(EXIT_FAILURE, _("failed to set terminal to raw mode"));
+
 	do {
 		rc = replay_get_next_step(setup, streams, &step);
 		if (rc)
@@ -300,6 +323,9 @@ main(int argc, char *argv[])
 		rc = replay_emit_step_data(setup, step, STDOUT_FILENO);
 	} while (rc == 0);

+	if (isterm)
+		tcsetattr(STDOUT_FILENO, TCSADRAIN, &saved);
+
 	if (step && rc < 0)
 		err(EXIT_FAILURE, _("%s: log file error"), replay_step_get_filename(step));
 	else if (rc < 0)
-- 
2.20.1