getty: set tty attrs so that control chars are shown as ^c

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 9 insertions, 8 deletions

diff --git a/loginutils/getty.c b/loginutils/getty.c
index 4b1b73bef..174542841 100644
--- a/loginutils/getty.c
+++ b/loginutils/getty.c
@@ -334,18 +334,19 @@ static void finalize_tty_attrs(void)
          *         observed to improve backspacing through Unicode chars
          */
 
-        /* line buffered input (NL or EOL or EOF chars end a line);
-         * recognize INT/QUIT/SUSP chars;
-         * echo input chars;
-         * echo BS-SP-BS on erase character;
-         * echo kill char specially, not as ^c (ECHOKE controls how exactly);
-         * erase all input via BS-SP-BS on kill char (else go to next line)
+        /* ICANON  line buffered input (NL or EOL or EOF chars end a line);
+         * ISIG    recognize INT/QUIT/SUSP chars;
+         * ECHO    echo input chars;
+         * ECHOE   echo BS-SP-BS on erase character;
+         * ECHOK   echo kill char specially, not as ^c (ECHOKE controls how exactly);
+         * ECHOKE  erase all input via BS-SP-BS on kill char (else go to next line)
+         * ECHOCTL Echo ctrl chars as ^c (else echo verbatim:
+         *         e.g. up arrow emits "ESC-something" and thus moves cursor up!)
          */
-        G.tty_attrs.c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE;
+        G.tty_attrs.c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE | ECHOCTL;
         /* Other bits in c_lflag:
          * XCASE   Map uppercase to \lowercase [tried, doesn't work]
          * ECHONL  Echo NL even if ECHO is not set
-         * ECHOCTL Echo ctrl chars as ^c (else don't echo) - maybe set this?
          * ECHOPRT On erase, echo erased chars
          *         [qwe<BS><BS><BS> input looks like "qwe\ewq/" on screen]
          * NOFLSH  Don't flush input buffer after interrupt or quit chars