in reply to get n lines before or after a pattern

Note you're output is not only showing 2 lines before the pattern, but also 1 line AFTER the pattern.

You don't need Perl for something that simple:

grep -B2 -A1 jack test.txt

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UPDATE: Since the OP updated the original question, this approach is no longer valid. See my reply (Re^3: get n lines before a pattern) below.

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Re^2: get n lines before a pattern
by darklord_999 (Acolyte) on Jul 25, 2012 at 14:55 UTC
    I have updated the details of my file. Please see the change . Sorry for the previous error.
[reply]

      Yes, the changes to the file in the OP certainly require an updated approach. What have you tried?

      I would loop through the file saving each key and either pushing to a data structure if the name matches or resetting and continuing.

      Pseudo code for the loop and structure I'd use:

      my @matches;
my $FOUND = 0;
my %info = {};
while (<INFILE>) {

   chomp $_;

   if (($_ =~ /^id/) and ($FOUND)) {
      push @matches \%info;
      $FOUND = 0;
      %info = {}
   }

   if ($_ =~ /^id/)      { (undef, $info{id})      = split / /, $_}
   if ($_ =~ /^address/) { (undef, $info{address}) = split / /, $_}
   if ($_ =~ /^name/)    { (undef, $info{fname})   = split / /, $_}
   ...

   if ($searchPattern eq $info{fname}) {
      $FOUND = 1;
   }
}

      [download]

      UPDATE: Added 'chomp' and updated 'split' commands as per kennethk suggestions to me.

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