I using curl to pull a hostname from a server using a HTTP get request, and that is working fine. I need my script to modify the /etc/sysconfig/network file so I don't have to restart the system to apply the hostname.
Here is my code thus far:
#!/usr/local/bin/perl
use strict;
use warnings;
use Sys::Hostname;
my $curl = `curl http://100.10.10.10/hostname`; # Get correct hostname
my $host = hostname;
if ($curl ne $host) {
# Need to modify the /etc/sysconfig/network file to replace hostname or add it.
}
EDIT:
My Actual Question: What is the best way for me to modify that file with the new hostname?
I guess you want is
my $host = qx{hostname};
instead of
my $host = hostname;
also, why dont you just make the changes manually (i.e, open /etc/hosts or whatever file you want to edit, and edit, just make sure the $> is 0... script is running as user root).
Related
Is there a cleaner way to do
use Sys::Hostname qw(hostname);
my $hostname = hostname();
$hostname =~ s/\.domain//;
Basically, is it possible to strip the hostname down to its short name without running two $hostname assignments and without additional modules?
You may use Net::Domain's hostname instead
Returns the smallest part of the FQDN which can be used to identify the host.
use Net::Domain qw(hostname);
my $hostname = hostname();
Without additional modules, call external command hostname -s
-s, --short
Display the short host name. This is the host name cut at the
first dot.
chomp(my $hostname = `hostname -s`);
Using Sys::Hostname:
use Sys::Hostname;
my ($short_hostname) = split /\./, hostname(); # Split by '.', keep the first part
Using system hostname command:
chomp(my ($short_hostname) = `hostname | cut -f 1 -d.`);
title: perl ssh to remote server, start service and capture pid
1-please tell me if i am not clear, or i if am otherwise frustrating as i ask questions - i do not want to bite the hand that feeds me!
2-original file is 180 lines long, but here is the gist:
#!/usr/bin/perl -w
use strict;
use warnings;
use Net::SSH::Perl;
use Net::SSH::Expect;
use Time::HiRes qw(usleep nanosleep);
Time::HiRes::sleep(5); #5 seconds #a look at "top" verifies this running .pl file pid.
my $remoteCmd = `ssh $remote_host -l $userID -i /home/$userID/.ssh/authorized_keys /sbin/service /etc/init.d/c3-mi-nodeserver start`;
my $servicePID = $$; #this should be pid for .pl file running.
print "servicePID: " . $servicePID . "\n"; #prints the pid of the running .pl file.
of course, you'll see variables that i populate to make it work.
one idea i have is: if i start a service, it will be the pid # of the currently running .pl file + 1; but, the new service started is on a remote server, so how can i capture it from the remote server and return it back to the local .pl file?
ideas?
With that ssh command there's no way to capture the PID of the process you just started on a remote host.
You would need to use another ssh to find the process id. But really - what are you trying to accomplish by doing so? Can you not use service status and service stop to manipulate it?
If you really need a pid - service status might do it - or running a ps command.
I'm unable to execute the HTML::Template function in the CGI.
I'm following a simple tutorial that I found here: http://metacpan.org/pod/HTML::Template
I created a new file on my server in the home path as test.tmpl.
I created a new file named frt.cgi ... (is that the issue here? should it be a different file extention??)
#!/usr/local/bin/perl -w
use HTML::Template;
# open the html template
my $template = HTML::Template->new(filename => '/test.html');
# fill in some parameters
$template->param(HOME => $ENV{HOME});
$template->param(PATH => $ENV{PATH});
# send the obligatory Content-Type and print the template output
print "Content-Type: text/html\n\n", $template->output;
I've modified the 1st line to reflect my host provided program path for perl. I don't know what the -w does I just know I've tried this with and without it. Also I've tried changing the code a bit like this:
use warnings;
use strict;
use CGI qw(:standard);
use HTML::Template;
I've searched...
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE+&submit=search
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE+PERL&submit=search
Yet I still do not see the answer.
I even searched google for .TMPL Encoding because I thought there may be some special type needed. Please help.
If you look in your server logs, you'll probably see an error message along the lines of:
HTML::Template->new() : Cannot open included file /test.html : file not found.
You need to provide the path on the file system, not a URI relative to the generated document.
First, you likely specified the wrong path - change /test.html to test.html.
Also, it is possible that there is no $ENV{HOME} variable in your system so set up flag die_on_bad_params to 0:
my $template = HTML::Template->new(
filename => 'test.html',
die_on_bad_params => 0,
);
Also, don't forget to mark your Perl file as executable by chmod 755.
Option -w makes Perl to enable warnings, so there is no point to write use warnings; afterwards.
You can check what Perl command line options do by using module B::Deparse, like this ($^W variable disables/enables warnings):
perl -w -MO=Deparse -e "print;"
This would print:
BEGIN { $^W = 1; }
print $_;
use Net::SSH::Perl;
my $ssh = Net::SSH::Perl->new('$host',22);
$ssh->login('$user','$pass');
my $out = $ssh->cmd("show clock");
print $out;
I have the above script to have an ssh session using perl but I'm having the error message
"Can't map service name 'ssh' to port number". I'm using Windows OS. Please advise me where I'm wrong.
Try adding ssh to your services file. The services file is located at:
%SystemRoot%\system32\drivers\etc\services
The line that you'll want to add will look like:
ssh 22/tcp # Secure Shell Login
Here How do I automate CPAN configuration? I've found some answers which led to some questions.
I tried cpan -j config.pm, but as far as I can see it is meant for per installation usage, not for changing the config-file permanently.
With the $CPAN::Config-method the force CPAN::FirstTime to not default to manual-part didn't work here so I tried without it:
#!/usr/bin/perl
use strict;
use warnings;
use Config;
use CPAN;
use CPAN::FirstTime;
$ENV{PERL_MM_USE_DEFAULT}=1;
$ENV{PERL_MM_NONINTERACTIVE}=1;
$ENV{AUTOMATED_TESTING}=1;
my $cpan_home = '/home/me/.cpan';
mkdir $cpan_home or die $! if not -d $cpan_home;
mkdir "$cpan_home/CPAN" or die $! if not -d "$cpan_home/CPAN";
CPAN::FirstTime::init( "$cpan_home/CPAN/MyConfig.pm" );
delete $CPAN::Config->{links};
$CPAN::Config->{applypatch} = '';
# ...
$CPAN::Config->{build_dir} = "$cpan_home/build";
$CPAN::Config->{cpan_home} = $cpan_home;
$CPAN::Config->{histfile} = "$cpan_home/histfile";
$CP$CPAN::Config->{keep_source_where} = "$cpan_home/sources";
$CPAN::Config->{make_install_make_command} = 'sudo make';
$CPAN::Config->{mbuild_install_build_command} = 'sudo ./Build';
$CPAN::Config->{prefs_dir} = "$cpan_home/prefs";
# ...
$CPAN::Config->{yaml_module} = 'YAML';
CPAN::HandleConfig->commit("$cpan_home/CPAN/MyConfig.pm");
CPAN::install('Bundle::CPAN');
# ...
# etc.
exit 0;
Is this OK? The only bad thing that I have noticed so far is the waiting, until the cpan-mirror-urls are found.
And what is the delete $CPAN::Config->{links}; for?
It looks like you are doing a lot of work. What are you trying to accomplish?
If you want to change the configuration file permanently, just change the configuration file. It's Perl code, so I think you can do everything you need, such as setting the root directory, right in the config file without having to deal with CPAN.pm.