blob: 2f65211bf8fa208bbded0684892c1449d8964861 (
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|
#!/bin/bash
BASH_ARGV0=twopane.bash
echo -n "$0" >/proc/$$/comm
set -e
set -f
set -o pipefail
shopt -s lastpipe
BOT_SIZE=8
BOT_TITLE=input
if [ $# = 0 ]
then
TOP_CMD="$SHELL -i"
BOT_CMD=foreground
TOP_EXIT=prompt
#BOT_CMD=start
#TOP_EXIT=restart
else
TOP_CMD=$*
BOT_CMD=start
TOP_EXIT=quit
fi
TOP_TITLE="Command: $TOP_CMD"
TWOPANE=$(mktemp -d)
export TWOPANE TOP_CMD BOT_CMD TOP_TITLE BOT_TITLE BOT_SIZE
trap 'rm -r "$TWOPANE"' EXIT
# STY=$(systemd-escape -p "$TWOPANE")
systemd_escape_path()
{
declare -g -n path="$1" result="$2"
result=$(realpath "$path")
result=${result//-/--}
result=${result//\//-}
}
systemd_escape_path TWOPANE STY
STY=$0.$$.$STY
save_file()
{
cat > "$TWOPANE"/"${1:?$0: Error: filename cannot be empty string}"
}
save_screenrc()
{
save_file screenrc"${1:+.$1}"
}
save_screenrc <<'.'
# Disable keybindings.
unbindall
escape \0\0
# Disable messages. This is needed for screen -X/-Q to work reasonably.
msgwait 0
msgminwait 0
# Try to disable blocking the terminal on ^S.
# Doesn't seem to work here.
# More is needed. Xterm?
nonblock on
caption string '%t'
layout new
split
focus bottom
resize $BOT_SIZE
screen -ln -t "$BOT_TITLE" 0 bash --noprofile --rcfile "$TWOPANE"/bashrc -i
layout save 0
.
check_screen_pane()
{
screen -p "$pane" -Q info >/dev/null
}
kill_screen_pane()
{
while check_screen_pane
do
screen -p "$pane" -X kill
done
}
start_screen_pane()
{
declare -g -a PANES
declare -i pane="${1:-1}"
(( pane > 0 )) || return
PANES+=("$pane")
if check_screen_pane "$pane"
then
return
fi
if [ $# = 0 ]
then
set -f
set -- ${TOP_CMD:-bash -i}
fi
TOP_TITLE="Command: ${*@Q}"
screen -X focus top
screen -X screen -ln -t "$TOP_TITLE" 1 "$@"
screen -p "$pane" -X exec .!. sh -c 'exec socat UNIX-LISTEN:"$TWOPANE"/socket STDIN,cfmakeraw!!STDOUT'
}
restart_screen_pane()
{
kill_screen_pane
start_screen_pane "$@"
}
# Start SOCAT if necessary.
# Connect the running SOCAT to file descriptors.
# Optionally assign the file descriptors to the specified variables.
# Optionally assign the socat PID to the specified variable.
#
# The copied file descriptors (unlike the original coprocess file
# descriptors, in ${SOCAT[0]} and ${SOCAT[1]}) can be passed to external
# processes (e.g.: other socat(1) instances) and used in subshells.
connect()
{
case $# in
3 )
declare -n pid="$1" std0="$2" std1="$3"
shift 3
;;
2 )
local pid
declare -n std0="$1" std1="$2"
shift 2
;;
0 )
local pid std0 std1
;;
* )
return 1
;;
esac
if ! [ "${SOCAT[0]}" ]
then
local STDERR
exec {STDERR}>&2
{
coproc SOCAT { socat_connect; } 2>&$STDERR
} 2>/dev/null
eval "exec $STDERR>&-"
fi
pid=${SOCAT_PID}
exec {std0}<&${SOCAT[0]} {std1}>&${SOCAT[1]}
disown
}
sendc()
{
[ "${SOCAT[0]}" ] || connect
printf '%s' "$*" >&${SOCAT[1]}
}
send()
{
[ "${SOCAT[0]}" ] || connect
printf '%s\n' "$*" >&${SOCAT[1]}
}
disconnect()
{
if [ $# = 2 ]
then
declare -i -n std0="$1" std1="$2"
eval "exec $std0<&- $std1>&-"
unset std0 std1
fi
wait -f "$SOCAT_PID" 2>/dev/null
}
restart()
{
start "$@"
}
start()
{
foreground "$@"
}
foreground_loop()
{
while true
do
start_screen_pane "$@"
connect stdin stdout
forward
disconnect stdin stdout
case "$TOP_EXIT" in
restart )
continue ;;
quit )
exit ;;
prompt | * )
focus bottom
break
;;
esac
done
}
forwarding()
{
[ "$FORWARD_PID" ] || return
FORWARD_JOBSPEC=$(jobs -sl | pid_to_jobspec "$FORWARD_PID")
[ "$FORWARD_JOBSPEC" ]
}
forward()
{
declare -g FORWARD_PID
if ! check_screen_pane
then
echo "$0: Warning: Nothing to forward. Starting anew." >&2
background "$@"
elif forwarding
then
resume_forward
return
fi
focus top
old_stty=$(stty -g)
# Lowercase $stdin/$stdout are the SOCAT coprocess connected to
# the other pane's terminal. Uppercase $STDIN/$STDOUT are the
# real stdin/stdout of this function, connected to the lower
# pane's terminal. Socat here merges inputs from both sources.
exec {STDIN}<&0 {STDOUT}>&1 {STDERR}>&2
# The input is put out raw back over the socket. The input is
# copied to stdout after being filtered (to display control
# characters with carrot-encoding like '^[' etc).
exec {TEE}> >(tee >(output_filter >&$STDOUT) >&$stdout)
stty=cfmakeraw,opost=1,onlcr=1
{
socat FD:$STDIN,$stty!!STDOUT - <&$stdin >&$TEE 2>&$STDERR &
} 2>/dev/null
FORWARD_PID=$!
printf '%s\n' "#!/bin/bash" "kill $!" "screen -X focus bottom" > "$TWOPANE"/unforward
chmod +x "$TWOPANE"/unforward
fg >/dev/null
stty "$old_stty"
focus bottom
echo
}
cfmakeraw()
{
cmd=(stty -ignbrk -brkint -parmrk -istrip -inlcr -igncr -icrnl
-ixon -opost -echo -echonl -icanon -isig -iexten -parenb cs8)
"${cmd[@]}" "$@"
}
pid_to_jobspec()
{
while read jspec pid status cmd
do
[ "$pid" = "$1" ] || continue
jspec=${jspec%]*}
jspec=%${jspec#[}
echo $jspec
return
done
false
}
resume_forward()
{
old_stty=$(stty -g)
cfmakeraw opost onlcr
focus top
fg "$FORWARD_JOBSPEC" >/dev/null
stty "$old_stty"
focus bottom
}
foreground()
{
if forwarding
then
resume_forward
else
foreground_loop "$@"
fi
}
twopane()
{
start "$@"
}
quit()
{
screen -X quit
}
focus()
{
screen -X focus "$@"
}
output_filter()
{
tokenize | colorize | soft_cursor
}
# if (show_nonprinting) {
# while (true)
# {
# if (ch >= 32) {
# if (ch < 127) *bpout++ = ch;
# else if (ch == 127) {*bpout++ = '^'; *bpout++ = '?';}
# else {
# *bpout++ = 'M';
# *bpout++ = '-';
# if (ch >= 128 + 32) {
# if (ch < 128 + 127) *bpout++ = ch - 128;
# else {*bpout++ = '^'; *bpout++ = '?';}}
# else {*bpout++ = '^'; *bpout++ = ch - 128 + 64;}}}
# else if (ch == '\t' && !show_tabs) *bpout++ = '\t';
# else if (ch == '\n') {newlines = -1; break;}
# else {*bpout++ = '^'; *bpout++ = ch + 64;}
# ch = *bpin++;}}
chr()
{
declare -i n="$*"
printf "\\$(printf %o "$n")"
}
colorize()
{
while read -r
do
case "$REPLY" in
\\[0-7][0-7][0-7] ) ;;
* )
printf '%s\n' "$REPLY"
continue
;;
esac
declare -i c=8#"${REPLY#?}"
if (( c > 128 + 127 ))
then
:
elif (( c > 128 + 32 ))
then
printf -v REPLY "M-$(chr c - 128)"
elif (( c > 127 ))
then
printf -v REPLY "M-^$(chr c - 128 + 64)"
elif (( c < 32 ))
then
printf -v REPLY "^$(chr c + 64)"
fi
printf $'\e[1m%s\e[m\n' "$REPLY"
done
}
tokenize()
{
while read -r -N1
do
if [[ "$REPLY" =~ [[:print:]] ]]
then
# Output one printable character per line. It may be a
# multibyte unicode character.
printf '%s\n' "$REPLY"
continue
else
# If it is a non-printable, then we output a
# multi-character line. In this case we colorize it
# later so that it won't be confused with multiple
# printable characters.
printf '\\%.3o\n' "'$REPLY"
continue
fi
done
}
soft_cursor()
{
FMT=$'%s \b\e[%sm \e[m\b'
REPLY=
while printf "$FMT" "$REPLY" $(( 101 + RANDOM % 7 ))
do
read -r || break
done
}
our_bashrc_main()
{
set -f
set -o pipefail
trap "screen -X quit" EXIT
export PS1="$BOT_TITLE\\\$ "
}
save_file bashrc <<.
BASH_ARGV0=twopane
echo -n "\$0" >/proc/\$\$/comm
${TOP_CMD@A}
${BOT_CMD@A}
${TOP_TITLE@A}
${BOT_TITLE@A}
${TOP_EXIT@A}
$(declare -f)
our_bashrc_main
$BOT_CMD
.
main()
{
screen -c "$TWOPANE"/screenrc -m -S "$STY" -ln
}
main "$@"
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