Shell Programming and Scripting

Hello everyone,

This is my first post here and this is the first time I am using UNIX OS (Slackware). I find it really useful and powerful and would like to master it but as you may guess I am expreicing quite a few problems.
I've been reading a few documentations about it and bash this week and now I am trying to make my first script (related to a task I got at the office) but I am really stuck. What I want it to do is make a list of all the open ports on the computer + the processes that have opened them + the number of files opened by each process. I tried using netstat with some of its options for the first two but it wouldn't work and for the last part I'm clueless.
I would be really grateful if anyone could help me.

Kindest regards

Try lsof -i, if its available.

which lsof would give a clue, on my system its located at /usr/sbin/lsof but i am using linux

Thanks for your suggestion but I think that it lists all processes on all ports without listing the port numbers and I would like to have them as well.

P.S.I'm also using Linux- Slackware.

It does lists the port numbers, but they get converted to service names from /etc/services. Try this:
lsof -i -P

Please check the man page for options that would be suitable for you.

Thanks very much, vish_indian.
I looked through the man page after you posted your first reply but I couldn't find what I needed. You were right that it lists the ports and now everything is fine with this.
What I am confused now with is that I want for everyone of the processes that are listed with lsof -i -P to make a list of all the files that each one is using. I looked at the reference and it's done with lsof -p PID, but is there a way to incorporate these two commands into one so that it lists the processes and the files without having to manually run the lsof -p command for each process separately.

I realized that the lsof -i -P does not list all the open ports and therefore I now use

Code:

netstat -tuv

instead. In order to find the process at each port I use

Code:

lsof -i:port number

which displays the process and the PID and now with

Code:

lsof -p PID > filelist.list;
wc -l filelist.list;

I display the number of files for each process. My problem is that in order to put this into a script I need to have access to the port numbers and PIDs. Is there a way of putting them into an array?

Thanks for your help.

A very crude script

Instead of echo $port--$pid you can use lsof -p $pid. Currently, this handles only tcp ports. for udp ports some changes may be required. I'll try to refine it more later. I am also assuming that you have awk(gawk).