• NAME
• SYNOPSIS
• DESCRIPTION
• SUBROUTINES
• EXAMPLE
• FREQUENTLY ASKED QUESTIONS
• GENERATING AND USING SSH KEYS
• AUTHORS
• COPYRIGHT
• BUGS
• SEE ALSO

NAME

Net::SSH - Perl extension for secure shell

SYNOPSIS

  use Net::SSH qw(ssh ssh_cmd issh sshopen2 sshopen3);

  ssh('user@hostname', $command);

  issh('user@hostname', $command);

  ssh_cmd('user@hostname', $command);
  ssh_cmd( {
    user => 'user',
    host => 'host.name',
    command => 'command',
    args => [ '-arg1', '-arg2' ],
    stdin_string => "string\n",
  } );

  sshopen2('user@hostname', $reader, $writer, $command);

  sshopen3('user@hostname', $writer, $reader, $error, $command);

DESCRIPTION

Simple wrappers around ssh commands.

For an all-perl implementation that does not require the system ssh command, see the Net::SSH::Perl manpage instead.

SUBROUTINES

ssh [USER@]HOST, COMMAND [, ARGS ... ]

Calls ssh in batch mode.

issh [USER@]HOST, COMMAND [, ARGS ... ]

Prints the ssh command to be executed, waits for the user to confirm, and (optionally) executes the command.

ssh_cmd [USER@]HOST, COMMAND [, ARGS ... ]

ssh_cmd OPTIONS_HASHREF

Calls ssh in batch mode. Throws a fatal error if data occurs on the command's STDERR. Returns any data from the command's STDOUT.

If using the hashref-style of passing arguments, possible keys are:

  user (optional)
  host (required)
  command (required)
  args (optional, arrayref)
  stdin_string (optional) - written to the command's STDIN

sshopen2 [USER@]HOST, READER, WRITER, COMMAND [, ARGS ... ]

Connects the supplied filehandles to the ssh process (in batch mode).

sshopen3 HOST, WRITER, READER, ERROR, COMMAND [, ARGS ... ]

Connects the supplied filehandles to the ssh process (in batch mode).

EXAMPLE

  use Net::SSH qw(sshopen2);
  use strict;

  my $user = "username";
  my $host = "hostname";
  my $cmd = "command";

  sshopen2("$user\@$host", *READER, *WRITER, "$cmd") || die "ssh: $!";

  while (<READER>) {
      chomp();
      print "$_\n";
  }

  close(READER);
  close(WRITER);

FREQUENTLY ASKED QUESTIONS

Q: How do you supply a password to connect with ssh within a perl script using the Net::SSH module?

A: You don't (at least not with this module). Use RSA or DSA keys. See the quick help in the next section and the ssh-keygen(1) manpage.

A #2: See the Net::SSH::Expect manpage instead.

Q: My script is ``leaking'' ssh processes.

A: See perlfaq8/``How do I avoid zombies on a Unix system'', the IPC::Open2 manpage, the IPC::Open3 manpage and perlfunc/waitpid.

GENERATING AND USING SSH KEYS

1. Generate keys
   Type:

      ssh-keygen -t rsa

   And do not enter a passphrase unless you wanted to be prompted for one during file copying.

   Here is what you will see:

      $ ssh-keygen -t rsa
      Generating public/private rsa key pair.
      Enter file in which to save the key (/home/User/.ssh/id_rsa):
      Enter passphrase (empty for no passphrase):

      Enter same passphrase again:

      Your identification has been saved in /home/User/.ssh/id_rsa.
      Your public key has been saved in /home/User/.ssh/id_rsa.pub.
      The key fingerprint is:
      5a:cd:2b:0a:cd:d9:15:85:26:79:40:0c:55:2a:f4:23 User@JEFF-CPU

2. Copy public to machines you want to upload to
   id_rsa.pub is your public key. Copy it to ~/.ssh on target machine.

   Put a copy of the public key file on each machine you want to log into. Name the copy authorized_keys (some implementations name this file authorized_keys2)

   Then type:

        chmod 600 authorized_keys

   Then make sure your home dir on the remote machine is not group or world writeable.

AUTHORS

Ivan Kohler <ivan-netssh_pod@420.am>

Assistance wanted - this module could really use a maintainer with enough time to at least review and apply more patches. Or the module should just be deprecated in favor of Net::SSH::Expect or made into an ::Any style compatibility wrapper that uses whatver implementation is available (Net::SSH2, Net::SSH::Perl or shelling out like the module does now). Please email Ivan if you are interested in helping.

John Harrison <japh@in-ta.net> contributed an example for the documentation.

Martin Langhoff <martin@cwa.co.nz> contributed the ssh_cmd command, and Jeff Finucane <jeff@cmh.net> updated it and took care of the 0.04 release.

Anthony Awtrey <tony@awtrey.com> contributed a fix for those still using OpenSSH v1.

Thanks to terrence brannon <tbone@directsynergy.com> for the documentation in the GENERATING AND USING SSH KEYS section.

COPYRIGHT

Copyright (c) 2004 Ivan Kohler. Copyright (c) 2007-2008 Freeside Internet Services, Inc. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

BUGS

Not OO.

Look at IPC::Session (also fsh, well now the native SSH ``master mode'' stuff)

SEE ALSO

For a perl implementation that does not require the system ssh command, see the Net::SSH::Perl manpage instead.

For a wrapper version that allows you to use passwords, see the Net::SSH::Expect manpage instead.

For another non-forking version that uses the libssh2 library, see the Net::SSH2 manpage.

For a way to execute remote Perl code over an ssh connection see the IPC::PerlSSH manpage.

ssh-keygen(1), ssh(1), the IO::File manpage, the IPC::Open2 manpage, the IPC::Open3 manpage