bash-com/bind-output

#!/bin/bash


# (1) Init.
#--------------------------------------------------------#
# (1) Get current absolute dir
ROOT=$(dirname `realpath $0`);

# (2) Check argc
test $# -lt 2 && echo -e "error: too fewarguments\n\n\e[1mUSAGE\e[0m\n\tbind-output <id> <ip> <port>\n\n\e[1mARGUMENTS\e[0m\n\t<id>\tThe identifier of the output (buffer name)\n\t<ip>\tThe ip or host of the target\n\t<port>\tThe port to connect to\n" && exit 1;

# (3) Check @PORT range #
MIN_PORT=1024;
MAX_PORT=49151;
test "$3" -gt "$MAX_PORT" -o "$3" -lt "$MIN_PORT" && echo "error: <port> must be between $MIN_PORT and $MAX_PORT" && exit 1;

# (4) Set argument explicit names #
OUT_ID="$1";
OUT_IP="$2";
OUT_PT="$3";



# (2) Prepare buffer
#--------------------------------------------------------#
# (1) Create buffer path
BUFFER="/tmp/outbuf_$OUT_ID";

# (2) Create/Flush buffer
test -f $BUFFER && rm $BUFFER;
touch $BUFFER;




# (3) Launch INPUT server
#--------------------------------------------------------#
(

	trap "kill -9 %1 2>/dev/null" INT KILL;
	outfail=0;

	# (1) kill script after 10 failures
.	while [ $outfail -lt 10 ]; do

		# (2) bind socket to buffer
		echo "(.) binding $BUFFER to $OUT_IP:$OUT_PT";

		( tail -f $BUFFER | nc $OUT_IP $OUT_PT 2> /dev/null && outfail="0" || ( outfail=`expr $outfail + 1`; exit 1 ) || echo "    * cannot access $OUT_IP:$OUT_PT" )&
		wait $!;

	done;

)&
LOOP_PID=$!;


# (2) Remove buffer + kill loop #
trap "rm $BUFFER 2>/dev/null; kill -9 $LOOP_PID 2>/dev/null" INT KILL;

wait $LOOP_PID;