1st time perl user requires help 1

[paulonline]

Hi all,

I have a question regarding perl that I hope you can help with.

I am trying to create an array from a hosts file, while at the same time removing unwanted lines, also i want to store only 2 of the colums from the file into the array.

--- hosts file example ---
#start of hosts file
10.0.2.10 machine1 mdlocal service1 service2
10.0.2.11 machine2 mdlocal service1 service2
#middle of hosts file

10.0.2.12 machine3 mdlocal service1
10.0.2.13 machine4

#end of hosts file

If I use the following code (with awk script I get the following output)

@get_host_list = `/usr/bin/grep mdlocal hosts | grep -v \"#\" | /usr/bin/awk \'\{print \$2,\$1\}\' | /usr/bin/sort -u` ;

print @get_host_list ;

output :-
machine1 10.0.2.10
machine2 10.0.2.11
machine3 10.0.2.12

So using perl only how would I extract column 1 & 2 and put only those values into the array.

Cheers
Paul

 

[feherke]

Hi

Like this ?

#!/usr/bin/perl

while (<DATA>) {
  chomp;
  $temp{join ' ',(split /\s+/)[1,0]}=1 if m/^[^#].*mdlocal/
}

@get_host_list=sort keys %temp;

print "$_\n" foreach (@get_host_list);

__DATA__
#start of hosts file
10.0.2.10 machine1 mdlocal service1 service2
10.0.2.11 machine2 mdlocal service1 service2
#middle of hosts file

10.0.2.12 machine3 mdlocal service1
10.0.2.13 machine4

#end of hosts file

Please use meaningful subjects in the future.

Feherke.

http://rootshell.be/~feherke/

 

[paulonline]

Excellent, exactly what I wanted.

Cheers

 

[tsuji]

This only offers an additional exercise with alternative pattern (hopefully tightening up to filter some undesired output, amid perhaps more exotic) and settings.
[tt]
#your givens here
[green]my $hostfile="c:\xyz\hosts";
my $outfile="c:\xyz\out.txt";[/green]

open(SRC,"<",$hostfile) or die "can't open $hostfile: $!";
open(TGT,">",$outfile) or die "can't open $outfile: $!";

while (<SRC>) {
if (/^\s*([^#\s]*?)\s+([^#\s]+?)\s+mdlocal.*$/) {
print TGT "$2 $1\n";
}
}

close TGT;
close SRC;[/tt]

 

[tsuji]

amendment
I've intended to forward slash the paths.
[tt]
#your givens here
[green]my $hostfile="c:[red]/[/red]xyz[red]/[/red]hosts";
my $outfile="c:[red]/[/red]xyz[red]/[/red]out.txt";[/green]
[/tt]