[Kc] Need second look at this...

[Garrett Goebel]

In order to fix your regex you'll need to tell us the difference  
between somehostpm1 and dr-somehostpm1.

Will a "good" somehostpm1 never be preceeded by 'dr-'? If so...

# Shot at adhering to Perl Best Practices
open my($file), '<', '/etc/hosts';
while (my $line = <$file>) {
     if ($line =~ /(?<!dr-)\S+pm1/) {
         print $line;
     }
}

# Quick'n Dirty
open FILE, '</etc/hosts';
map { print if /(?<!dr-)\S+pm1/ } <FILE>;

I haven't tested it... perhaps it'll work.

(?<!pattern) is a zero width negative look behind assertion. I.e.  
it'll match anything that isn't preceeded by the pattern without  
including it in the match.

Garrett

On Oct 11, 2007, at 2:44 PM, Emmanuel Mejias wrote:

> trying to grep out some info from my /etc/hosts file...just to get  
> more practice with Perl and well for my personal pleasure, too.
>
> #!/usr/bin/perl
>
> open (FILE, "/etc/hosts");
> @lines = <FILE>;
> close (FILE);
>
> foreach $line (@lines){
>    if ($line =~ /pm1/){
>       print $line;
>    }
> }
>
> the problem with this is that it's printing out some hosts that i  
> don't want that also have pm1 at the end.
>
> somehostpm1 but it also gets my dr hosts (dr-somehostpm1)
>
> thoughts?
>
> by the way, i had to jump the wifes car so i ended up missing out  
> on the meeting. gonna try to make the next one for sure, though.
>
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