Diff two remote files using Perl - perl

Question

I have an array of file paths:
#files = ('/home/.../file.txt', '/home/.../file2.txt',...);
I have multiple remote machines, with a similar filestructure. How can I diff these remote files using Perl?
I thought of using Perl backticks, ssh and using diff, but I am having issues with sh (it doesn't like diff <() <()).
Is there a good Perl way of comparing at least two remote files?

Answer 1

Use rsync to copy the remote files to the local machine, then use diff to find out the differences:
use Net::OpenSSH;
my $ssh1 = Net::OpenSSH->new($host1);
$ssh1->rsync_get($file, 'master');
my $ssh2 = Net::OpenSSH->new($host2);
system('cp -R master remote');
$ssh2->rsync_get($file, 'remote');
system('diff -u master remote');

Answer 2

You can use the Perl Module on CPAN called Net::SSH::Perl to run remote commands.
Link: http://metacpan.org/pod/Net::SSH::Perl
Example from the Synopsis:
use Net::SSH::Perl;
my $ssh = Net::SSH::Perl->new($host);
$ssh->login($user, $pass);
my($stdout, $stderr, $exit) = $ssh->cmd($cmd);
You command would look something like
my $cmd = "diff /home/.../file.txt /home/.../file2.txt";
edit: The files are on different servers.
You can still use Net::SSH::Perl to read the files.
#!/bin/perl
use strict;
use warnings;
use Net::SSH::Perl;
my $host = "First_host_name";
my $user = "First_user_name";
my $pass = "First_password";
my $cmd1 = "cat /home/.../file1";
my $ssh = Net::SSH::Perl->new($host);
$ssh->login($user, $pass);
my($stdout1, $stderr1, $exit1) = $ssh->cmd($cmd1);
#now stdout1 has the contents of the first file
$host = "Second_host_name";
$user = "Second_user_name";
$pass = "Second_password";
my $cmd2 = "cat /home/.../file2";
$ssh = Net::SSH::Perl->new($host);
$ssh->login($user, $pass);
my($stdout2, $stderr2, $exit2) = $ssh->cmd($cmd2);
#now stdout2 has the contents of the second file
#write the contents to local files to diff
open(my $fh1, '>', "./temp_file1") or DIE "Failed to open file 1";
print $fh1 $stdout1;
close $fh1;
open(my $fh2, '>', "./temp_file2") or DIE "Failed to open file 2";
print $fh2 $stdout2;
close $fh2;
my $difference = `diff ./temp_file1 ./temp_file2`;
print $difference . "\n";
I haven't tested this code, but you could do something like this. Remember to download the Perl Module Net::SSH::Perl to run remote commands.
Diff is not implemented in the Perl Core Modules, but there another called Text::Diff on CPAN so maybe that would work too. Hope this helps!