match multi-lines from config file

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

Hi all
I am trying to match a similar set of lines from a config file and store the results in a hash.

interface Port-channel31
 description abc.xyz-conf
 no ip address
 load-interval 60
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 15-17,30,35,120,130,135,140,145,150,201
+,202,209
[download]

My approach is :
1. Find a line starting with string "interface".
2. Search the next following line with "description abc.xyz-conf"
3. Search the next following line with "switchport trunk allowed vlan 15-17,30,35,120,130,135,140,145,150,201,202,209"
4. Store the key-value pair for each descriptio-vlans found.
- Similar patterns are to be searched across the config.
Can someone suggest how do I go about doing this in perl.
Any help appreciated.

Comment on match multi-lines from config file Download Code

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Re: match multi-lines from config file by GrandFather (Saint) on Aug 06, 2007 at 22:57 UTC
Use open to open a file handle then use: `while (<IN>) {` [download] to scan the file. Use index or a regular expression match to skip (using next) until the interface line is found. Skip until the description line is found: `/^description/ && last while <IN>; my $description = $_;` [download] Process the description then use the same technique for the rest of the lines you need to match. DWIM is Perl's answer to Gödel	[reply] [d/l] [select]
Re^2: match multi-lines from config file by mreece (Friar) on Aug 07, 2007 at 06:23 UTC
`/^description/ && last while <IN>;` that confused the heck out of me! how about this form? `$_ = <IN> until /^description/;` [download] doh!	[reply] [d/l] [select]
Re^3: match multi-lines from config file by GrandFather (Saint) on Aug 07, 2007 at 10:41 UTC
Because that tests $_ before the first value is assigned to it and doesn't terminate for a file that doesn't include a matching line! DWIM is Perl's answer to Gödel	[reply]
Re: match multi-lines from config file by xicheng (Sexton) on Aug 07, 2007 at 04:28 UTC
An easy way for this kind of problems is to reset the IRS $/, say: `use strict; use warnings; use Data::Dumper; my %hash = (); { local $/ = "interface "; while(<DATA>) { my ($key) = /description\s+(.)/; next if $key =~ /^\s$/; my ($value) = /switchport trunk allowed vlan\s(.)/; $hash{$key} = $value; } print Dumper \%hash; __DATA__ .....` [download] Make sure the IRS won't show up within each block, so make it more specific accordingly... Regards, Xicheng	[reply] [d/l]
Re: match multi-lines from config file by nidhi (Acolyte) on Aug 10, 2007 at 17:29 UTC
Thanku very much all, it really helped me!!	[reply]