Simple Problem getting me Stumped

CongoGrey has asked for the wisdom of the Perl Monks concerning the following question:

I have a flat file that is large enough to fit into memory and all i want to do is read the file line by line and if the line contains a specific value 'read_community XXXXX' print 'read_community newstring'. Here is where I am at:

open NCNODE, "/path/nervecenter.node"
    or die "Error opening Nerve Center Node file ($!)";
foreach my $variable (<NCNODE>) {
    chomp;
    print STDOUT $variable;
}
close NCNODE;
[download]

I know that i need to place an if statement where i have the print line. But, i guess i am having an issue with the syntax. I was thinking that it would be something like:

if ($variable eq 'read_community'){
    print;
}
[download]

But, it does not seem to be correct. Below is a sample of the file.

begin node
name Router
on_off on
group Frame_Relay
suppress no
auto_delete yes
read_community readstring
write_community readstring
address 10.0.0.0
port 161
snmp_version 1
engineid 0
auth_protocol 0
is_key_ok 1
error_status 0
security_level 0
end node
[download]

Comment on Simple Problem getting me Stumped Select or Download Code

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Re: Simple Problem getting me Stumped by KPeter0314 (Deacon) on Jul 01, 2003 at 17:07 UTC
You could use something simple like the power of $_ and a while like this: `open NCNODE, "/path/nervecenter.node" or die "Error opening Nerve Center Node file ($!)"; while (<NCNODE>) { chomp; if (/read_community/) { print; } } close NCNODE;` [download] -Kurt	[reply] [d/l]
Re: Re: Simple Problem getting me Stumped by CongoGrey (Sexton) on Jul 01, 2003 at 17:33 UTC
Thanks KPeter that way worked like a champ. Thanks for your help.	[reply]
Re: Simple Problem getting me Stumped by dws (Chancellor) on Jul 01, 2003 at 17:08 UTC
Since you're trying to match a leading substring, use a regular expression. `if ( $variable =~ /^read_community/ ) { ...` [download] should do it. Note that there's one other problem in your code. `chomp;` [download] should be `chomp($variable);` [download]	[reply] [d/l] [select]
Re: Simple Problem getting me Stumped by ant9000 (Monk) on Jul 01, 2003 at 17:09 UTC
A one liner doing that: `perl -pe's/^(read_community)\s+XXXXXX/\1 newstring/'` [download]	[reply] [d/l]