Awk script to select range from file

jeesun · 11-25-2009, 03:20 AM

I have a file generated in every event occurred. In this file i have a entries like bellow

<without blank line after Summary>
Summary:
Adapter at hardware path 0/6/1/0 : Received an interrupt indicating that a
primitive was transmitted

and sometimes like bellow

<with blank line after Summary>
Summary:

Adapter at hardware path 0/6/1/0 : Received an interrupt indicating that a
primitive was transmitted

What I need is to extract the Summary from the file. I have the following awk script. But it only works if there is no blank line after Summary.

cat server.event.txt|awk '/^Sum/,/^$/'

But I need up to second blank lines after Summary.

Can anyone correct the script?

berbae · 11-25-2009, 05:27 AM

I propose

Code:

sed -n '/^Summary/!p
/^Summary/ {N
s/\n$//
p}' eventfilename |sed -n '/^Summary/,/^$/p'

You don't need awk for that.
The first sed suppresses a blank line after a line beginning with Summary.
The second sed extracts the lines between Summary and the next blank line.

jeesun · 11-25-2009, 05:53 AM

Output error

#sed -n '/^Summary/!p /^Summary/ {N s/\n$// p}' bldhkilm.event.txt |sed -n '/^Summary/,/^$/p'
sed: Function /^Summary/!p /^Summary/ {N s/\n$// p} cannot be parsed.

jschiwal · 11-25-2009, 06:02 AM

Could you post an actual sample containing both cases. It is hard to test an answer without test data. Sometimes a description of the problem isn't enough. I'm not certain whether there is more than one line of textafter "Summary"; whether there is always a blank line before "Summary"; or whether there are blank lines elsewhere. Be sure to post the last summary record. Whether there is a blank line after the last summary could determine whether a "/Summary:/,/^$/" range will match for the last summary.

You shouldn't have joined the lines in the example barbea posted.

Code:

cat summaryexample
Summary:
This is a non blank line right after the Summary heading.
This is a part of the summary.

Summary:

There is a blank line after the summary.
The last line of the file is blank.

Code:

sed -n '/^Summary/!p
        /^Summary/ {N
                    s/\n$//
                    p}' summaryexample |
sed -n '/^Summary/,/^$/p'
Summary:
This is a non blank line right after the Summary heading.
This is a part of the summary.

Summary:
There is a blank line after the summary.
The last line of the file is blank.

It is important to use proper indentation so that the structure of the sed program stands out. That way you can see easily which commands are executed only in a range or subrange.

jeesun · 11-25-2009, 06:05 AM

I have posted it my initial post.

berbae · 11-25-2009, 11:40 AM

For the command to work, it should have been launched as written in my post, or in jschiwal's one with a better identation (the line structure has to be kept).
Can you confirm that it solves your problem ?

jeesun · 11-25-2009, 09:52 PM

Using Jschiwal's code my output is like bellow

$ sed -n '/^Summary/!p
> /^Summary/ {N
> s/\n$//
> p}' bldhkilm.event.txt |
> sed -n '/^Summary/,/^$/p'
sed: Function p} cannot be parsed.

BTW, my OS is HP-UX

berbae · 11-26-2009, 05:21 AM

The command works in Linux.
But it seems that in HP-UX each sed command should be on its own line so try :

Code:

sed -n '/^Summary/!p
        /^Summary/ {N
                    s/\n$//
                    p
                    }' bldhkilm.event.txt |
sed -n '/^Summary/,/^$/p'

And Jschiwal's code is the same code I've written in post #2 with a different presentation.
The "sed: Function p} cannot be parsed." should have given you a clue that the HP-UX sed command doesn't like the } just after the command p.
I hope that it will be the good answer now.

jeesun · 11-26-2009, 05:46 AM

Thanks a lot barbae, finally it works

Very much appreciate for your contribution.