UNIX for Dummies Questions & Answers

Hi
I really hope someone can help with the below question.
Lets say that I have a file called output.txt and I want to display all of the lines which contain the word ‘disconnect'. I know that this can easily be obtained by using the following command:
grep -i disconnect output.txt

However, the next task is a bit trickier. Lets say that I don't want to print the line with the keyword ‘disconnect' but rather I am interested in displaying the line immediately below the that line. The line below the line which has the word ‘disconnect' could contain anything, such as an IP address or a string. How would I achieve that? For instance, the second line would be displayed in the below example:
Error, disconnect from server
The following machine as affected: IP 101.256.33.44

Many Thanks

Code:

awk '/disconnect/ { getline; print $0;}' <inputfile>

Like this?

Code:

connect
connect
disconnect
that one
connect
disconnect
that one too
connect
$> awk '/^disco/ {getline; print}' infile
that one
that one too

Hi .. if u have "disconnect" in consecutive lines .... the first alone printing not the second line.

Example : a file has three line
--------------

Error disconnect :
Error disconnect 1
Error in 1 line:

Here the second line "Error disconnect 1" is printing not the "Error in 1 line:"

@girija:
It depends on where in the consecutive lines the string "disconnect" is placed so you could maybe check by this if it should be printed or not. But to make sure:

@Sunny Sid:
To reduce the chance of errors and guessing around please post an excerpt of your input file and the expected output, ty. Please use code tags when doing so.

I think it would be helpful.

Code:

bash-3.00$ cat sample.txt
connect
connect
disconnect
that one
connect
disconnect
that one too
connect
disconnect
disconnect
connect
connect
disconnect
that one too
bash-3.00$

Code:

 grep -A 1 "disconnect" sample.txt | grep -v "disconnect"

Hi
Thanks for all of the replies. The input file would not contain the keyword 'disconnect' on two consecutive lines. Additionally, 'disconnect' may not necessarily appear at the start of a line. I just want the line below the line containing 'disconnect' to appear. Here is a sample from the input file:
connect
connect
disconnect
that one
connect
disconnect
that one too
connect

... and this would be the output:
that one
that one too

For the above situation would both the following commands achieve the same result:

awk '/disconnect/ { getline; print $0;}' <inputfile>
grep -A 1 "disconnect" sample.txt | grep -v "disconnect"

If so then I would be more keen on using grep | grep to do the job because I am still quite unfamilar with awk.