Avoid needing to initialize tty state in bootstrap scripts

shell-integration/ssh/bootstrap.py

@@ -16,7 +16,7 @@ import tempfile
 import termios
 
 tty_fd = -1
-original_termios_state = None
+echo_on = int('ECHO_ON')
 data_dir = shell_integration_dir = ''
 request_data = int('REQUEST_DATA')
 leading_data = b''
@@ -25,11 +25,12 @@ login_shell = pwd.getpwuid(os.geteuid()).pw_shell or 'sh'
 
 
 def cleanup():
-    global tty_fd, original_termios_state
+    global tty_fd
     if tty_fd > -1:
-        if original_termios_state is not None:
-            termios.tcsetattr(tty_fd, termios.TCSANOW, original_termios_state)
-            original_termios_state = None
+        if echo_on:
+            s = termios.tcgetattr(tty_fd)
+            s[3] |= termios.ECHO
+            termios.tcsetattr(tty_fd, termios.TCSANOW, s)
         os.close(tty_fd)
         tty_fd = -1
 
@@ -150,7 +151,6 @@ def get_data():
     data = []
     with open(tty_fd, 'rb', closefd=False) as f:
         data = b''.join(iter_base64_data(f))
-    cleanup()
     if leading_data:
         # clear current line as it might have things echoed on it from leading_data
         # because we only turn off echo in this script whereas the leading bytes could
@@ -214,26 +214,11 @@ def exec_with_shell_integration():
 
 
 def main():
-    global tty_fd, original_termios_state, login_shell
+    global tty_fd, login_shell
+    tty_fd = os.open(os.ctermid(), os.O_RDWR | os.O_CLOEXEC)
     try:
-        tty_fd = os.open(os.ctermid(), os.O_RDWR | os.O_CLOEXEC)
-    except OSError:
-        pass
-    else:
-        if request_data:
-            try:
-                original_termios_state = termios.tcgetattr(tty_fd)
-            except OSError:
-                pass
-            else:
-                new_state = termios.tcgetattr(tty_fd)
-                new_state[3] &= ~termios.ECHO
-                termios.tcsetattr(tty_fd, termios.TCSANOW, new_state)
-    try:
-        if original_termios_state is not None:
-            send_data_request()
-        if tty_fd > -1:
-            get_data()
+        send_data_request()
+        get_data()
     finally:
         cleanup()
     cwd = os.environ.pop('KITTY_LOGIN_CWD', '')

shell-integration/ssh/bootstrap.sh

@@ -2,14 +2,14 @@
 # Copyright (C) 2022 Kovid Goyal <kovid at kovidgoyal.net>
 # Distributed under terms of the GPLv3 license.
 
-saved_tty_settings=""
 tdir=""
 shell_integration_dir=""
+echo_on="ECHO_ON"
 
 cleanup_on_bootstrap_exit() {
-    [ -n "$saved_tty_settings" ] && command stty "$saved_tty_settings" 2> /dev/null < /dev/tty
+    [ "$echo_on" = "1" ] && command stty "echo" 2> /dev/null < /dev/tty
+    echo_on="0"
     [ -n "$tdir" ] && command rm -rf "$tdir"
-    saved_tty_settings=""
     tdir=""
 }
 
@@ -58,18 +58,6 @@ else
     die "base64 executable not present on remote host, ssh kitten cannot function."
 fi
 
-init_tty() {
-    saved_tty_settings=$(command stty -g 2> /dev/null < /dev/tty)
-    tty_ok="n"
-    [ -n "$saved_tty_settings" ] && tty_ok="y"
-
-    if [ "$tty_ok" = "y" ]; then
-        command stty -echo 2> /dev/null < /dev/tty || die "stty failed to set raw mode"
-        return 0
-    fi
-    return 1
-}
-
 dcs_to_kitty() { printf "\033P@kitty-$1|%s\033\134" "$(printf "%s" "$2" | base64_encode)" > /dev/tty; }
 debug() { dcs_to_kitty "print" "debug: $1"; }
 echo_via_kitty() { dcs_to_kitty "echo" "$1"; }
@@ -84,11 +72,8 @@ leading_data=""
 login_cwd=""
 
 request_data="REQUEST_DATA"
-[ "$request_data" = "1" ] && init_tty
 trap "cleanup_on_bootstrap_exit" EXIT
-if [ "$tty_ok" = "y" -a "$request_data" = "1" ]; then
-    dcs_to_kitty "ssh" "id="REQUEST_ID":pwfile="PASSWORD_FILENAME":pw="DATA_PASSWORD""
-fi
+dcs_to_kitty "ssh" "id="REQUEST_ID":pwfile="PASSWORD_FILENAME":pw="DATA_PASSWORD""
 record_separator=$(printf "\036")
 
 mv_files_and_dirs() {
@@ -177,18 +162,16 @@ get_data() {
     untar_and_read_env
 }
 
-if [ "$tty_ok" = "y" ]; then
-    # ask for the SSH data
-    get_data
-    cleanup_on_bootstrap_exit
-    if [ -n "$leading_data" ]; then
-        # clear current line as it might have things echoed on it from leading_data
-        # because we only turn off echo in this script whereas the leading bytes could
-        # have been sent before the script had a chance to run
-        printf "\r\033[K" > /dev/tty
-    fi
-    [ -f "$HOME/.terminfo/kitty.terminfo" ] || die "Incomplete extraction of ssh data"
+# ask for the SSH data
+get_data
+cleanup_on_bootstrap_exit
+if [ -n "$leading_data" ]; then
+    # clear current line as it might have things echoed on it from leading_data
+    # because we only turn off echo in this script whereas the leading bytes could
+    # have been sent before the script had a chance to run
+    printf "\r\033[K" > /dev/tty
 fi
+[ -f "$HOME/.terminfo/kitty.terminfo" ] || die "Incomplete extraction of ssh data"
 
 login_shell_is_ok() {
     if [ -n "$login_shell" -a -x "$login_shell" ]; then return 0; fi
@@ -282,14 +265,6 @@ shell_name=$(command basename $login_shell)
 # If a command was passed to SSH execute it here
 EXEC_CMD
 
-if [ "$tty_ok" = "n" ]; then
-    if [ -z "$(command -v stty)" ]; then
-        printf "%s\n" "stty missing ssh kitten cannot function" > /dev/stderr
-    else
-        printf "%s\n" "stty failed ssh kitten cannot function" > /dev/stderr
-    fi
-fi
-
 exec_zsh_with_integration() {
     zdotdir="$ZDOTDIR"
     if [ -z "$zdotdir" ]; then