Attached is a patch that turns on INTR/QUIT/SUSP echoing in the N_TTY
line discipline (e.g. ctrl-C will appear as "^C" if stty echoctl is set
and ctrl-C is set as INTR).
Linux seems to be the only unix-like OS (recently I've verified this on
Solaris, BSD, and Mac OS X) that does *not* behave this way, and I
really miss this as a good visual confirmation of the interrupt of a
program in the console or xterm. I remember this fondly from many Unixs
I've used over the years as well. Bringing this to Linux also seems
like a good way to make it yet more compliant with standard unix-like
behavior.
The fix is pretty trivial. Let me know if you think this is a candidate
for inclusion in the kernel.
Thanks, Joe
--- linux-2.6.22-gentoo-r9/drivers/char/n_tty.c 2007-07-08 17:32:17.000000000
-0600
+++ linux-2.6.22-gentoo-r9.new/drivers/char/n_tty.c 2007-12-06
07:16:56.000000000 -0700
@@ -760,7 +760,22 @@
signal = SIGTSTP;
if (c == SUSP_CHAR(tty)) {
send_signal:
- isig(signal, tty, 0);
+ /*
+ * Echo character, and then send the signal.
+ * Note that we do not use isig() here because we want
+ * the order to be:
+ * 1) flush, 2) echo, 3) signal
+ */
+ if (!L_NOFLSH(tty)) {
+ n_tty_flush_buffer(tty);
+ if (tty->driver->flush_buffer)
+ tty->driver->flush_buffer(tty);
+ }
+ if (L_ECHO(tty)) {
+ echo_char(c, tty);
+ }
+ if (tty->pgrp)
+ kill_pgrp(tty->pgrp, signal, 1);
return;
}
}
