asked on

read input file line by line and get the number from second column

I have a output file like the following format.

david 9428 1 0 May12 ? 00:00:00 udt PHANTOM TEST1
david 9429 1 0 May12 ? 00:00:00 udt PHANTOM TEST1
david 9401 1 0 May12 ? 00:00:00 udt PHANTOM TEST1
david 9404 1 0 May12 ? 00:00:00 udt PHANTOM TEST1
david 9408 1 0 May12 ? 00:00:00 udt PHANTOM TEST1

Read the file as an input, then what I want to do is to get all of the second column number, which are process ids, and kill the process.

I'm running Linux 6.0 and kernel is 2.4. Please give a sample for bash script. Thanks in advance!

ASKER CERTIFIED SOLUTION

sunnycoder

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SOLUTION

ravenpl

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root_start

Hi lijunguo,

There are several ways you can do this, as some suggested above and I am giving another way:
==============================================================
cut -f6 -d" " <file> | xargs kill -15
==============================================================

I suggested above the "cut" command because it is faster than "awk", also, I suggested "kill -15" because the "15" lets the process to finish and not kills it abort.

The command above will report if the process you are trying to kill does not exist but if you don't want this message, just:
==============================================================
cut -f6 -d" " txt | xargs kill -15 2>> /dev/null
==============================================================

I hope it helps. =0)

SOLUTION

Tintin

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root_start

Hi Tintin,

Thanks for the check you sent me, the "cut" command depends on the length of username and I didn't know that.

In my opinion, if you have more that one user that you want to kill a process, you can use Tintin's command:
============================================================
kill `awk ' { print $2 } ' filename `
============================================================

But if the processes have the same username, you can use:
==============================================================
cut -f6 -d" " txt | xargs kill -15 2>> /dev/null
==============================================================

Sorry about my half correct answer.

root_start

Hi Again lijunguo,

As I told you in my first comment, there are several ways to do what you need.

Check the following:
==============================================================
perl -nae 'print @F[1];print "\n"' | xargs kill -15
==============================================================

Again, I hope it helps. =0)

root_start

Ops...

I forgot to put one thing in my last command above:
==============================================================
perl -nae 'print @F[1];print "\n"' <file> | xargs kill -15
==============================================================

lijunguo

ASKER

Hi Guys,
I really appreciate your quick help. But "sunnycoder" provides an easy and simple solution, and works perfect. And it's good to know some alternatives.

Regards,
Lijunguo