---
name: "Net::SSH"
section: "3pm"
platform: "linux"
package: "libnet-ssh-perl"
version: "0.09-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Net::SSH"
---

# Net::SSH(3pm)

Perl extension for secure shell

## 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 Net::SSH::Perl 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)](/ssh-keygen/1.md) manpage.

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

Q: My script is "leaking" ssh processes.

A: See "How do I avoid zombies on a Unix system" in perlfaq8, IPC::Open2, IPC::Open3 and "waitpid" in perlfunc.

## 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 Net::SSH::Perl instead.

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

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

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

[**ssh-keygen**(1)](/ssh-keygen/1.md), [**ssh**(1)](/ssh/1.md), IO::File, IPC::Open2, IPC::Open3