Perl Script to Read file and Modify.

Need Perl script to assist with the following:  I need to modify a configuration parameter file based on the environment it is to run on.  Ninety-eight percent of the file is static and does not change.  One definition is missing, and the hostname needs to be updated based on the environment configuration; other than that the file is static.  My plan is to use a file template, whereas 99% of the file is exactly as it should be and good to go; and then use a tag, i.e. “<hostname>” to denote what my global substitution.  I would like to read in my Oracle database network configuration file and updated it with added entry plus the actual hostname based on the host the script will be executed on.
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What have you tried?
In what way is your code failing?
What errors does your code produce?

Please post your script and sample config file.

You could do something like this one liner:
perl -pe "s/<hostname>/$ENV{'COMPUTERNAME'}\nMISSING DATA/" < config.txt > config.cfg

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sdrussAuthor Commented:
Can't do one-liner.  This need to be part of an existing script.  Not able to post the actual script.  

No code is failing as it doesn't exist yet. So there for no errors.
First you say it needs to be part of an existing script then you say the code doesn't exist.  That's contradictory.

Start by doing a search on for config and template to find relevant modules.  Then run some tests using one or more of those modules.  When you get stuck, post your short but complete test script that we can run to duplicate and troubleshoot the problem.
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sdrussAuthor Commented:
Don't want to argue.  If you don't want to help -don't.  New code I'm interested in adding doesn't exist.  I will not be able to post anything based on my work environment.  Posting anything from my environment is a show-stopper.  It that was the case I would have posted initially.
I don't want to argue either but if you're unwilling to spend a few minutes attempting to solve your problem, why should anyone else spend the time?  I don't ask that to be argumentative; it's a legitimate and honest question.

Here's a tested script.

use strict;
use warnings;
use Template;

my $vars = { hostname => $ENV{'hostname'} };
my $template = Template->new;
$template->process('config.tmpl', $vars);

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The var in the template is:
[% hostname %]

The output defaults to going to STDOUT but you can send it to a file instead.

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FYI, you can also use the Text::Template module which has fewer dependencies and the syntax is almost identical.
sdrussAuthor Commented:
My work environment is in a closed network by design, and this makes it difficult to share details.  Appreciate your help!
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