From 6c5d87d2ba239424f6127d0ff0c51e668d590773 Mon Sep 17 00:00:00 2001
From: xdrm-brackets <doowap31@gmail.com>
Date: Tue, 30 Jan 2018 18:46:00 +0100
Subject: [PATCH] fix: actual 'failures' management (.5s between each failure +
 stop after 10 consecutive ones) + on success do as usual

---
 bind-input | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/bind-input b/bind-input
index 15dfac5..c250d81 100755
--- a/bind-input
+++ b/bind-input
@@ -10,8 +10,8 @@ ROOT=$(dirname `realpath $0`);
 test $# -lt 2 && echo -e "error: too fewarguments\n\n\e[1mUSAGE\e[0m\n\tbind-input <id> <port>\n\n\e[1mARGUMENTS\e[0m\n\t<id>\tThe identifier of the input (buffer name)\n\t<port>\tTo port to listen to\n" && exit 1;
 
 # (3) Check @PORT range #
-MIN_PORT=49152;
-MAX_PORT=65535;
+MIN_PORT=1024;
+MAX_PORT=49151;
 test "$2" -gt "$MAX_PORT" -o "$2" -lt "$MIN_PORT" && echo "error: <port> must be between $MIN_PORT and $MAX_PORT" && exit 1;
 
 # (4) Set argument explicit names #
@@ -36,19 +36,31 @@ touch $BUFFER;
 #--------------------------------------------------------#
 (
 
-	trap "kill -9 %1 2>/dev/null" INT KILL;
+	trap "kill -9 $NC_PID 2>/dev/null" INT KILL;
 	infail=0;
 
 	# (1) kill script after 10 failures
 	while [ $infail -lt 10 ]; do
 
-		echo "failures: $infail";
-
 		# (2) bind socket to buffer
-		echo "(.) binding :$IN_PT to $BUFFER";
+		echo "(.) binding port $IN_PT to $BUFFER";
 
-		( nc -lp $IN_PT >> $BUFFER 2> /dev/null && infail="0" || ( infail=`expr $infail + 1`; exit 1 ) || echo "    * cannot access :$IN_PT" )&
-		wait $!;
+		# (3) Check if port already in use
+		ss -tl4 "( sport = :$IN_PT )" | grep "$IN_PT" >/dev/null;
+		PORT_TAKEN=$?;
+
+		# (4) Manage taken port #
+		if [ "$PORT_TAKEN" -ne "1" ]; then
+			infail="`expr $infail + 1`";
+			sleep .5;
+			continue;
+		fi;
+
+		# (5) Bind input
+		infail="0";
+		( nc -lp $IN_PT >> $BUFFER 2>/dev/null )&
+		NC_PID=$!;
+		wait $NC_PID;
 
 	done;