Help to extract the content in this string

bala041 · #1 (**permalink**) 11-25-2008

Hi All,

I have a string in the following format:
"kf skjgsdjgngnsd sdgsd

ksjgbksjgb kjsbgsjdgb
dfhdh

sjgsjg j jsbekgjsbdkgj".

In this format i want to extract the contents which is in between the two empty lines: i.e, i want to extract the following
"ksjgbksjgb kjsbgsjdgb
dfhdh ".

Please help me in this. Thanks in advance.

Regards,
Bala

zaxxon · #2 (**permalink**) 11-25-2008

What did you try so far?

Code:

sed -n '/^$/,/^$/ {/^[^ ]/p}' infile
ksjgbksjgb kjsbgsjdgb
dfhdh

bala041 · #3 (**permalink**) 11-25-2008

Hi,
I'm a beginer in UNIX. I have tried using cut with regular expressions. but that doesnt work.The Problem is i'll not be having the string in a file. It comes out of some other operations and the format of that o\p is as given below in the previous post.
can u please explain me the command u gave, what is the use of that infile. The String will be dynamic. it can be anything but only the pattern will be same. That is i have to extract all the string between two new lines.

Thanks in advance,
Bala

zaxxon · #4 (**permalink**) 11-25-2008

You should be able to pipe your output just into that sed command.
infile is just the filename I saved your example on my harddisk and I feed sed not with a pipe in front of it but just with this infile.

If the output you want to parse varies a lot, you can't go like that. You have to know how your output looks as close as possible.

Code:

sed -n              # Print only the stuff we want to see; else it prints all 
                    # the stuff it is processing additionally
'                   # Here starts the regex and commands
/^$/,/^$/           # The / starts and ends a pattern; ^ is the start of a
                    # line, $ the end of a line and since nothing is specified 
                    # between it, it must be an empty line. So writing two 
                    # patterns separated with a comma is like giving a 
                    # range "from" "to"
{/^[^ ]/p}          # When the range is separated, do the command in curled
                    # braces. The command inside the braces says to get a
                    # pattern, that does not start with a blank. Inside square brackets the ^ means "not". The p simply stands for print.


' infile

bala041 · #5 (**permalink**) 11-25-2008

Hi,
I tried the following thing.
comment1 = $(echo "$comment1" | sed -n '/^$/,/^$/ {/[^ ]/p}').

where comment1 has the string which shuld be formatted. But it's saying that:
sed: command garbled: /^$/,/^$/ {/[^ ]/p}.

Is there anything wrong with the regex we are using.

Regards,
Bala

zaxxon · #6 (**permalink**) 11-25-2008

I am not sure what you are going to do. If you echo "$comment1", what do you get? Is the output you want to parse in a variable? If it is just the output of a command, try using that command and put a pipe | behind that command followed by the sed command. If it is a file, use it as I did above. If there is no reason to force the text into a variable, don't do it.

npatwardhan · #7 (**permalink**) 11-25-2008

try saving that string to a file.its easier that way even though you have to create a file.

you can then use:

string = `more <filename>`

then use the string variable to extract that text with the sed command.

you can always delete the file once you are done with rm.

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
extract a string from main string	madhu.it	Shell Programming and Scripting	1	10-06-2008 04:05 AM
extract a sub string from a main string	madhu.it	Shell Programming and Scripting	5	10-04-2008 02:22 AM
Extract content from several txt-files	larsu	Shell Programming and Scripting	7	06-17-2008 03:52 AM
Content extract of a file using awk	nr_shan	Shell Programming and Scripting	5	12-19-2007 05:22 AM
How to extract a portion of a string from the whole string	ds_sastry	UNIX for Dummies Questions & Answers	2	09-29-2001 10:40 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread: