Regex in shell scripting

[learingperl01]

Hello everyone,

wondering if someone could please help me with the following problem. In the code shown below currently I am just running a search for any files that match dc001.anything.log. and then each log file that it finds I printout everything after the forth line. What I am trying to do is instead of printing everything after the fourth line I would like to print everything after a regex match for a string. For example if I have a file like the one below, I would like to match on the last occurrence of 'CONNECTION' then print everything after that match. I am pretty new to shell scripting so I am not even sure if this can be done.

#!/bin/sh

DIR=$1

cd ${DIR}
find . -name 'dc001\.*\.log' -print | \
while read log
do
  tail +5 ${log} > ${log}.deleting
  mv ${log}.deleting ${log}
done


SAMPLE FILE

CONNECTION
CONNECTION
RESET
CONNECTION
BLAH
BLAH
BLAH
IP ADDRESS
BLAH

Based on the sample file above the script should yield the following results/output.

BLAH
BLAH
BLAH
IP ADDRESS
BLAH

thanks for the the help in advance.

 

[feherke]

Hi

One way, probably the ugliest :

tac /input/file | sed -n '/CONNECTION/q;p' | tac > /output/file

Feherke.

http://rootshell.be/~feherke/

 

[feherke]

Hi

A nicer but memory wasting solution with [tt]awk[/tt] :

awk '$0=="CONNECTION"{delete(b);n=0;next}{b[n++]=$0}END{for(i=0;i<n;i++)print b[i]}' /input/file > /output/file

An efficient solution as we learned from PHV :

awk 'FNR==NR&&$0=="CONNECTION"{n=FNR}FNR!=NR&&FNR>n' /input/file /input/file > /output/file

Feherke.

http://rootshell.be/~feherke/

 

[columb]

Something along the lines of

#!/bin/ksh

IFS='
'

while read line
do
  [[ "$line" = CONNECTION ]] && { > /output/file; } || { echo $line >> /output/file; }
done < /input/file

i.e. every time it comes to a line that matches CONNECTION it resets the output file. Not very efficient but another way to do it.


On the internet no one knows you're a dog

Columb Healy

 

[PHV]

I don't know why (;-)) but I like the last feherke's suggestion:

awk 'FNR==NR&&$0=="CONNECTION"{n=FNR}FNR!=NR&&FNR>n' $log $log > $log.$$ && mv $log.$$ $log

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[columb]

Given that your name is 'learning perl' try

perl -e 'my @op;while (<>) {/CONNECTION/ and @op=(), next or push @op, $_;} print @op;' $log > $log.$$ && mv $log.$$ $log

On the internet no one knows you're a dog

Columb Healy

 

[learingperl01]

columb..

Dude thanks for the help. I completely forgot that I could do this is a perl one liner you are the MAN I was able to put that in my code successfully.

thanks for the help everyone.