topic Re: PERL help needed by newbie in Operating System - Linux

PERL help needed by newbie

exec22 — Tue, 17 May 2005 12:16:20 GMT

After trying to figure this out on my own using the "camel book" over 4 hours and testing, I broke down. I am sure it is a very simple command/commands to accomplish what I am trying to do but I could not acomplish what I wanted to do.

Here is my problem:

I have few files on each of my servers with around a thousand lines in each, from which I need to make a simple search and replace. File format is simple:

ParameterName Value

where both ParameterName and Value are alphanumeric strings, e.g.,

FilesystemThreshold 92%
LargefileValue 9999999

what I need to do is to search for the ParameterName and replace the value to a preset string on the same line, but this line may repeat itself multiple times (repetition count varies from one file to the other) in this file and I have to do the replacement on every each occurance of the ParameterName.

What would be a simple one or two liner perl command to accomplish this ?

Thank you for your help.

Re: PERL help needed by newbie

Steven E. Protter — Tue, 17 May 2005 12:20:16 GMT

The following thread, with me asking the question contains the perl code you need:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=830280

This one is also useful.
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=780662

Its not breaking down to ask a question. Its efficient use of your time.

Please do not hesitate to ask again.

SEP

Re: PERL help needed by newbie

harry d brown jr — Tue, 17 May 2005 13:16:52 GMT

Why not just use "sed" ??

Here are two ways with sed:

(1) On the command line:

sed -e "s/$ParameterName1$ $.*$/\1 MyAnswer/g" -e "s/$ParameterName3$ $.*$/\1 YourAnswer/g" -e "s/$ParameterName5$ $.*$/\1 TheAnswer/g" ./testparams > NEWFILENAME

(2) Create a file with the parameters that need changing:

vi testvalues
Add lines like this:
s/$ParameterName1$ $.*$/\1 MyAnswer/g
s/$ParameterName3$ $.*$/\1 YourAnswer/g
s/$ParameterName5$ $.*$/\1 TheAnswer/g

sed -f testvalues ./testparams > NEWFILENAME

Here it is in action (without the redirect output to a new file):

[root@rndspt01 /tmp]# cat testparams
ParameterName1 hello
ParameterName1 test
ParameterName2 mom
ParameterName3 there
ParameterName4 why
ParameterName5 This is strange
ParameterName3 where
[root@rndspt01 /tmp]# sed -e "s/$ParameterName1$ $.*$/\1 MyAnswer/g" -e "s/$ParameterName3$ $.*$/\1 YourAnswer/g" -e "s/$ParameterName5$ $.*$/\1 TheAnswer/g" ./testparams
ParameterName1 MyAnswer
ParameterName1 MyAnswer
ParameterName2 mom
ParameterName3 YourAnswer
ParameterName4 why
ParameterName5 TheAnswer
ParameterName3 YourAnswer

OR with the use of a parameter file:

[root@rndspt01 /tmp]# cat testvalues
s/$ParameterName1$ $.*$/\1 MyAnswer/g
s/$ParameterName3$ $.*$/\1 YourAnswer/g
s/$ParameterName5$ $.*$/\1 TheAnswer/g
[root@rndspt01 /tmp]# sed -f ./testvalues ./testparams
ParameterName1 MyAnswer
ParameterName1 MyAnswer
ParameterName2 mom
ParameterName3 YourAnswer
ParameterName4 why
ParameterName5 TheAnswer
ParameterName3 YourAnswer
[root@rndspt01 /tmp]#

live free or die
harry d brown jr

Re: PERL help needed by newbie

Rodney Hills — Tue, 17 May 2005 15:54:40 GMT

Run the following one line on each server-

perl -pe 'BEGIN{$p=shift ; $v=shift ;}{s/ .*/ $v/ if /^$p /o}' ParameterName Value file1 file2 ... filen

HTH

-- Rod Hills

Re: PERL help needed by newbie

Rodney Hills — Tue, 17 May 2005 16:21:20 GMT

Forgot the '-i' option

perl -pi -e 'BEGIN{$p=shift ; $v=shift ;}{s/ .*/ $v/ if /^$p /o}' ParameterName Value file1 file2 ... filen

-- Rod Hills

Re: PERL help needed by newbie

exec22 — Wed, 28 Dec 2005 19:39:41 GMT

thanks