Shell Programming and Scripting

cat /opt/lastports
124

cat /opt/usedports  #simulation I will used netstat -lntu to look used port
21
22
23
110
111
120
126
127

#!/bin/sh

clear
echo ""
LASTPORT=$(cat /opt/port/lastports)  #Get the last port
NEWTMPPORT=$(( $LASTPORT + 1 ))  #Get the last port add 1 and sum

#PORTCHECKER=$(netstat -lntu |tail -n +3 |awk '{print $4}' |rev |cut -f1 -d: |rev |sort -u |grep $NEWTMPPORT) # look new temporary port to the list
PORTCHECKER=$(cat /opt/port/usedports | grep $NEWTMPPORT)

if [ "$PORTCHECKER" == "$NEWTMPPORT" ]; then  #if new port is equal to port checker then assign other port
NEWPORT=$(( $NEWTMPPORT + 1 ))

echo "LASTPORT    is $LASTPORT"          #this not importat for checking
echo "NEWTMPPORT  is $NEWTMPPORT"          #this not importat
echo "PORTCHECKER is $PORTCHECKER"          #this not importat
echo "NEWPORT     is $NEWPORT"          #this not importat

else
echo "$NEWPORT Port is available!"
fi

for i in `eval echo {$NEWTMPPORT..$NEWPORT}`
do
echo $i
done

LASTPORT=32767
ss | awk ' /\*/ {print $6 } > portlist.txt

getport {
   result="FAIL"
   for (( i=8193; i<$LASTPORT; i++))
   do
         grep -q "$i" portlist.txt && continue
         result="$i"
         break
   done
   echo "$result"
}
# usage
port=$( getport )
if [ "$port" = "FAIL" ] ; then
   echo "no ports available"
   exit
fi
# use the port number here

i=8193

 sh test1.sh
test1.sh: line 2: unexpected EOF while looking for matching `''
test1.sh: line 21: syntax error: unexpected end of file

ss | awk ' /\*/ {print $6 } > portlist.txt

ss | awk ' /\*/ {print $6 }' > portlist.txt

for (( var=initial_val; var < test_value; var++ ))

#!/bin/sh
CHECKTHIS=$(cat /opt/curport)
CHECKTHISPORT=$CHECKTHIS
func_checker () {
USEDPORTS=$(netstat -ntpl |awk '{print $4}' |rev |cut -f1 -d: |rev |sort -u |head -n -2 |grep $CHECKTHISPORT)
if [ "$CHECKTHISPORT" == "$USEDPORTS" ]; then
CHECKTHISPORT=`expr $CHECKTHISPORT + 1`
func_checker
else
   echo "$CHECKTHISPORT is available!"
fi
}
func_checker