A better grep

linutzy · 03-29-2010, 09:22 AM

I have data inside a file that looks something like this:

---------------------------------------------------------

This.is.top/this.is.the.file.info.2010-03-26-07.gz:010101,010101:9899900
Car N USDIOUY F0000009248754308
Big y USDDELL R8982313804198034

This.is.another/this.is.the.file.info.2010-03-26-08.gz:01010,11111:99999
Bird Y USDIUYY T9876343978438794
Cat Y USD1234 U9362489736182374
Dog N USDDELL P8716234789126412
---------------------------------------------------------

I want it so that when I grep for a specific word I also get the top portion. Essentially, I need to grep in this case DELL, but my output should be like this:

This.is.top/this.is.the.file.info.2010-03-26-07.gz:010101,010101:9899900
Big y USDDELL R8982313804198034

This.is.another/this.is.the.file.info.2010-03-26-08.gz:01010,11111:99999
Dog N USDDELL P8716234789126412
------------------------------------------

I am able to do a simple grep for just:

Big y USDDELL R8982313804198034
Dog N USDDELL P8716234789126412

But I need the top section also, please and thanks.

AlucardZero · 03-29-2010, 09:35 AM

grep -B1

(man grep)

Tinkster · 03-29-2010, 02:11 PM

awk is my weapon of choice in this case

Code:

$ awk 'BEGIN{RS=ORS="";FS=OFS="\n"} /DELL/ {printf "%s\n",$1;for(i=2;i<=NF;i++){if($i ~ /DELL/){printf "%s\n",$i}};printf "\n"}' file 
This.is.top/this.is.the.file.info.2010-03-26-07.gz:010101,010101:9899900
Big y USDDELL R8982313804198034

This.is.another/this.is.the.file.info.2010-03-26-08.gz:01010,11111:99999
Dog N USDDELL P8716234789126412

You can make it more flexible by using a shell-script
wrapper and putting DELL into a variable.

Cheers,
Tink

mahu_mahu · 04-01-2010, 10:50 AM

Just FYI, you might want to read the section 4.1.3 of "Classic Shell Scripting" from O'REILLY.