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Delete lines with a word and their above lines


 
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# 1  
Delete lines with a word and their above lines

Hi, i have a file like this:

Code:
A1
kdfjdljfdkljfdlf

A2
lfjdlfkjddkjf

A3
***no hit***

A4
ldjfldjfdk

A5
***no hit***

A6
jldfjdlfjdlkfjd

I want to remove the lines "***no hit*** and their above line to get an output file like this:
Code:
A1
kdfjdljfdkljfdlf

A2
lfjdlfkjddkjf

A4
ldjfldjfdk

A6
jldfjdlfjdlkfjd

Thanks!!


Moderator's Comments:
Mod Comment Use code tags please, see PM.

Last edited by zaxxon; 07-19-2013 at 10:46 AM.. Reason: code tags
# 2  
Code:
awk 'NF{v=$0;getline;if($0!="***no hit***") print v RS $0 RS " "}' file

This User Gave Thanks to Yoda For This Post:
# 3  
Quote:

Code:
awk 'NF{v=$0;getline;if($0!="***no hit***") print v RS $0 RS " "}' file

Hello Yoda,

Sorry to bother you, could you please explaoin this great command of awk.
I will be grateful to you.


Thanks,
R. Singh
# 4  
Code:
awk '
        # If NF ( Number of Fields ) not equal to zero
        NF {
                # Set variable v = $0 ( current record )
                v = $0
                # Explicitly read next input record
                getline
                # If $0 ( current record ) != "***no hit***"
                if ( $0 != "***no hit***" )
                        # Print variable v value RS ( Record Separator - newline by default ) $0 RS blank space " "
                        print v RS $0 RS " "
        }
' file

This User Gave Thanks to Yoda For This Post:
# 5  
Thanks a lot Yoda, I have no hesitation to say you are one of the champs for awk. It's really pleasure to read/follow your posts. Smilie



Thanks,
R. Singh
# 6  
Yoda,

I just tried your awk script but i get an error @ line 3 i.e v=$0. As i'm pretty new to awk i could not make out what could be the problem. And also one more doubt what i have is:

Ravinder wanted to delete the line before the ***no hit*** also but with the logic what i understood the below script will print the line A3 and then check for ***no hit*** condition rite..?


bash-3.00# awk '
> NF
> {
> v=$0
> getline
> if ($0!="***no hit***")
> print v RS $0 RS " "
> '
awk: syntax error near line 3
awk: bailing out near line 3
# 7  
Use nawk instead in Solaris or SunOS
 

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