grep for a particular pattern and remove few lines above top and bottom of the patter Post: 302171846

Sponsored Content

Top Forums Shell Programming and Scripting grep for a particular pattern and remove few lines above top and bottom of the patter Post 302171846 by drl on Friday 29th of February 2008 05:41:36 PM

02-29-2008

Registered User

Hi.

Using an older tool, the programmable interactive line editor ed or ex:

Code:

#!/usr/bin/env sh

# @(#) s3       Demonstrate deleting a range with line editor.

#  ____
# /
# |   Infrastructure BEGIN

echo
set -o nounset

debug=":"
debug="echo"

## The shebang using "env" line is designed for portability. For
#  higher security, use:
#
#  #!/bin/sh -

## Use local command version for the commands in this demonstration.

EDITOR=ex
EDITOR=ed

set +o nounset
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version =o $(_eat $0 $1) $EDITOR
set -o nounset

echo

FILE=data1
cp sacred $FILE
echo " Input file $FILE:"
cat $FILE

before=5
after=6
pattern="pattern"

# |   Infrastructure END
# \
#  ---

echo
echo " Output from editor $EDITOR:"
$EDITOR <<EOF $FILE
/$pattern/-${before},/$pattern/+${after}d
w
q
EOF
echo
echo " Output file $FILE:"
cat $FILE

exit 0

Producing:

Code:

% ./s3

(Versions displayed with local utility "version")
Linux 2.6.11-x1
GNU bash, version 2.05b.0(1)-release (i386-pc-linux-gnu)
GNU ed version 0.2

 Input file data1:
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
pattern
1
2
3
4
5
6
7
8
9
10

 Output from editor ed:
60
25

 Output file data1:
-10
-9
-8
-7
-6
7
8
9
10

I like this approach for small jobs because the syntax of the range is so understandable -- from the pattern so many lines back, to the pattern plus so many lines forward.

A disadvantage is that this can be slow on large files because the entire file is read.

See man pages for details ... cheers, drl

( edit 1: typo )

Last edited by drl; 02-29-2008 at 07:28 PM..

drl

View Public Profile for drl

Find all posts by drl

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to search for a pattern from bottom to top.

Hi, I have a file, which is having a pattern "SEARCH" somewhere towards end of the file, if i am giving " grep -i "SEARCH" $File" , it is taking too much time as file is very big. So i want to search for the pattern from the back side of the file, how can we search for a pattern in bottom...

2. UNIX for Dummies Questions & Answers

Grep for a pattern based on another patter

hi, I have looked at many grep threads and am unable to find something like this: please help. I have a file which is generated from a report generator and i am trying to load a whole lot of specific data into a table for the users. One field is causing me problems.All the rest i can manage....

3. Shell Programming and Scripting

Search for string and print top and bottom line

Hi Folks I need a one liner to parse through a log and if the string is found print the line above, the line with the string and the line below. example: The ball is green and blue Billy through the ball higer. Jane got hurt with the ball. So if I search for Billy I would need the 3...

4. Shell Programming and Scripting

Remove x lines form top and y lines form bottom using AWK?

How to remove x lines form top and y lines form bottom. This works, but like awk only cat file | head -n-y | awk 'NR>(x-1)' so remove last 3 lines and 5 firstcat file | head -n-3 | awk 'NR>4'

5. Shell Programming and Scripting

Print n lines from top and n lines from bottom of all files with .log extenstion

Oracle Linux 6.4 In a directory I have more than 300 files with the extension .log I want the first 5 and last 5 lines of these .log files to be printed on screen with each file's name. Expected output : Printing first 5 and last 5 lines of FX_WT_Feb8_2014.log !! Authentication...

6. Ubuntu

Title bar top and bottom

Hello forum, Seems that only I have alot of questions regarding Ubuntu :D In Ubuntu 12.04 LTS the gnome I have been using gdm and lightdm. In lightdm the top and side bars are aka "unity" and can be removed using apt-get remove unity I need to do the same for menu bars gdm. I do not...

7. Shell Programming and Scripting

How to print from bottom to top?

Hi, i have a file which contains PID and wanted to execute kill command. but the thing is, when killing PID's needs to kill PID from bottom to top. Please help INPUT 21414 sh -c extract.ksh ASA 21416 /bin/ksh extract.ksh ASA 21428 /usr/bin/perl -w /var/tmp/tempperl.21416 ASA...

8. Shell Programming and Scripting

Remove top and bottom for each column

Dear All I was wondering if someone could help me in resolving an issue. I have a file like this: column1 column2 2 4 3 5 8 9 0 12 0 0 0 0 9 0 87 0 1 0 1 0 1 0 4 0

9. Shell Programming and Scripting

Removing top few and bottom few rows in a file

Hi, I have a requirement where I need to delete given number of top and bottom rows in a flat file which has new line as its delimiter. For ex: if top_rows=2 & bottom_rows=1 Then in a given file which looks like: New York DC LA London Tokyo Prague Paris Bombay Sydney...

LEARN ABOUT MINIX

grep

GREP(1) 						      General Commands Manual							   GREP(1)

NAME

       grep - search a file for lines containing a given pattern

SYNOPSIS

       grep [-elnsv] pattern [file] ...

OPTIONS

       -e     -e pattern is the same as pattern

       -c     Print a count of lines matched

       -i     Ignore case

       -l     Print file names, no lines

       -n     Print line numbers

       -s     Status only, no printed output

       -v     Select lines that do not match

EXAMPLES

       grep mouse file	   # Find lines in file containing mouse

       grep [0-9] file	   # Print lines containing a digit

DESCRIPTION

       Grep  searches  one  or	more  files (by default, stdin) and selects out all the lines that match the pattern.  All the regular expressions
       accepted by ed and mined are allowed.  In addition, + can be used instead of * to mean 1 or more occurrences, ? can be used to mean 0 or  1
       occurrences,  and  |  can  be used between two regular expressions to mean either one of them.  Parentheses can be used for grouping.  If a
       match is found, exit status 0 is returned.  If no match is found, exit status 1 is returned.  If an error is detected,  exit  status  2	is
       returned.

SEE ALSO

       cgrep(1), fgrep(1), sed(1), awk(9).

																	   GREP(1)