Re: Using a lookup table(?)

Open the file into an array or hash?

Assuming I understand you correctly, and you are using a file of the format:

server1             Webserver
server2             DMZ Server
server4             Oracle Server
[download]

you could do the following:

use strict;
use Tie::File;
  |
  mumble.
  |

sub get_comments {
   my $host=shift;
   my @ry=();
   tie @ry,"Tie::File","myfile.txt" or die "myfile.txt: $!";
   my @lines = grep $host,@ry;
   my $line = shift @lines;  # should only be one. 
   my @f=split(/[\s\n\t]+/,$line);
   shift @f;
   untie @ry;
   return join(" ",@f);
}
[download]

Keep in mind I haven't tested this and this is off the top of my head. There's some error detection logic missing in that code (for instance, nothing for the value $host in the input file) and stuff like that.

Hope this is a help...

Peter L. Berghold -- Unix Professional
Peter -at- Berghold -dot- Net; AOL IM redcowdawg Yahoo IM: blue_cowdawg

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Re^2: Using a lookup table(?) by ikegami (Patriarch) on Feb 07, 2007 at 18:16 UTC
Your ignored the fact that the search was case-insensitive. `my $host = lc(shift(@_));` [download] Your `grep` is wrong. `my @lines = grep { lc($_) eq $host } @ry;` [download] Why read the whole file everytime? `use List::Util qw( first ); my $line = first { lc($_) eq $host } @ry;` [download] Why use Tie::File if you're not going to take advantage of it? `use List::Util qw( first ); my $line = first { lc($_) eq $host } <$fh>;` [download] Why load up the entire file into memory if you look at it one line at a time? `sub get_comments { my $host = lc(shift(@_)); my $file_name = "myfile.txt"; open(my $fh, '<', $file_name) or die("Unable to open server info file \"$file_name\": $!\n"); while (<$fh>) { return $1 if /^$host:\s(.)/; } return; }` [download] Of course, that's still very expensive if `get_comments` is called repeatedly. If the list is really that long, some sort of index (or database) would be very useful. A sorted file with fixed length records would also be fine (allowing for a binary search).	[reply] [d/l] [select]
Re^3: Using a lookup table(?) by blue_cowdawg (Monsignor) on Feb 07, 2007 at 19:22 UTC
Why load up the entire file into memory if you look at it one line at a time? Last I checked... Tie::File does not load the entire file into memory... Peter L. Berghold -- Unix Professional Peter -at- Berghold -dot- Net; AOL IM redcowdawg Yahoo IM: blue_cowdawg	[reply]
Re^4: Using a lookup table(?) by ikegami (Patriarch) on Feb 07, 2007 at 19:27 UTC
That comment refered to the intermediary step towards the optimization that used `<$fh>` in list context. Tie::File does not load the entire file in memory (although it stores in memory the index of every line encountered in the file, unrelated and beyond any limit you have placed on its cache size).	[reply] [d/l]