Shell Programming and Scripting

Hello,

I'm still a beginner at this so I hope someone would explain this basic stuff to me. I have the following function:

Code:

showProcesses()
{
	netstat -atuv | awk '{print $4}' > ports.list
	lsof -i < ports.list | awk 'NR>1{print $1}'
}

and the output for lsof -i < ports.list varies: sometimes its one line, sometimes more than one. I want to display only the first line of it (without removing the awk formatting).
Thanks in advance.

Kindest regards,
Valentin

Can you provide your requirement with examples
it would be better to give solution on time...

You can add

head -1

head -1 seems to cut all of the output lines.
Here is what I have as output:

dhcpcd #corresponds to first output
sshd #correspond to sencond output
psi #corresponds to third output
psi #third output
rdesktop #forth output

As you see there are cases when

Code:

lsof -i < ports.list

lists one process and cases when it lists two. I want when it lists two or more to take only the first one (i.e. the first line of output for this case ).

Change 'NR>1{print $1}' to 'NR==2{print $1}'

Changing NR==2 causes only one line of output to be displayed for the whole lsof -i<ports.list and what I would like to do is to have the first line of every output.

Change
to

Code:

lsof -i < ports.list | awk 'NR>1{print $1}' | sort | uniq