script to scan ports using nc command

Iyyappan · 08-02-2012, 04:52 AM

Hi All,
I am using nc to scan ports. But I need to scan only two different ports. I have written script for one port.

#!/bin/sh

DATE=`date +%h-%d-%Y_%H:%M`
for port in 3220
do
# echo $port
/usr/bin/nc -z *.*.*.* 3220
if [ $? -eq 0 ]
then
echo $port is Up
else
echo $port is Down on $DATE
fi
done

But I need to scan port 52000 port too in the script, kindly guide me how to do this

evo2 · 08-02-2012, 05:00 AM

Hi,

seems you need to learn how to use for loops.
Here is and example:

Code:

for p in 3220 52000
do
  echo $p
done

Evo2.

anomie · 08-02-2012, 11:45 AM

Or use a proper port-scanning utility like nmap(1).

(Don't get me wrong; nc(1) is a beautiful utility with many purposes. But only being able to scan single ports or ranges - without the help of a wrapper script - is annoying.)

Iyyappan · 08-04-2012, 09:57 AM

I used two scripts separately for two ports.

#!/bin/sh

/usr/bin/nc -z -w 5 localhost 52000 > /dev/null
if [[ $? -eq 0 ]]
then
echo 0
else
echo 1
fi

#!/bin/sh

/usr/bin/nc -z -w 5 localhost 6280 > /dev/null
if [[ $? -eq 0 ]]
then
echo 0
else
echo 1
fi

anomie · 08-04-2012, 12:34 PM

If you're going to completely ignore our advice, then at least consider eliminating the redundant if-else constructs (in each of your redundant scripts).

Iyyappan · 08-04-2012, 11:53 PM

Anomie,
I did use your suggestion for another server. I had placed two scripts because, I was in a hurry to complete that day itself.