4 use vars qw($VERSION @ISA @EXPORT_OK $ssh $equalspace $DEBUG @ssh_options);
6 use POSIX ":sys_wait_h";
13 @EXPORT_OK = qw( ssh issh ssh_cmd sshopen2 sshopen3 );
22 Net::SSH - Perl extension for secure shell
26 use Net::SSH qw(ssh issh sshopen2 sshopen3);
28 ssh('user@hostname', $command);
30 issh('user@hostname', $command);
32 ssh_cmd('user@hostname', $command);
37 args => [ '-arg1', '-arg2' ],
38 stdin_string => "string\n",
41 sshopen2('user@hostname', $reader, $writer, $command);
43 sshopen3('user@hostname', $writer, $reader, $error, $command);
47 Simple wrappers around ssh commands.
49 For an all-perl implementation that does not require the system B<ssh> command,
50 see L<Net::SSH::Perl> instead.
56 =item ssh [USER@]HOST, COMMAND [, ARGS ... ]
58 Calls ssh in batch mode.
63 my($host, @command) = @_;
64 @ssh_options = &_ssh_options unless @ssh_options;
65 my @cmd = ($ssh, @ssh_options, $host, @command);
66 warn "[Net::SSH::ssh] executing ". join(' ', @cmd). "\n"
71 =item issh [USER@]HOST, COMMAND [, ARGS ... ]
73 Prints the ssh command to be executed, waits for the user to confirm, and
74 (optionally) executes the command.
79 my($host, @command) = @_;
80 my @cmd = ($ssh, $host, @command);
81 print join(' ', @cmd), "\n";
87 =item ssh_cmd [USER@]HOST, COMMAND [, ARGS ... ]
89 =item ssh_cmd OPTIONS_HASHREF
91 Calls ssh in batch mode. Throws a fatal error if data occurs on the command's
92 STDERR. Returns any data from the command's STDOUT.
94 If using the hashref-style of passing arguments, possible keys are:
99 args (optional, arrayref)
100 stdin_string (optional) - written to the command's STDIN
105 my($host, $stdin_string, @command);
108 $host = $opt->{host};
109 $host = $opt->{user}. '@'. $host if exists $opt->{user};
110 @command = ( $opt->{command} );
111 push @command, @{ $opt->{args} } if exists $opt->{args};
112 $stdin_string = $opt->{stdin_string};
114 ($host, @command) = @_;
118 my $reader = IO::File->new();
119 my $writer = IO::File->new();
120 my $error = IO::File->new();
122 my $pid = sshopen3( $host, $writer, $reader, $error, @command ) or die $!;
124 print $writer $stdin_string if defined $stdin_string;
127 my $select = new IO::Select;
128 foreach ( $reader, $error ) { $select->add($_); }
130 my($output_stream, $error_stream) = ('', '');
131 while ( $select->count ) {
132 my @handles = $select->can_read;
133 foreach my $handle ( @handles ) {
135 my $bytes = sysread($handle, $buffer, 4096);
136 if ( !defined($bytes) ) {
137 waitpid($pid, WNOHANG);
138 die "[Net::SSH::ssh_cmd] $!"
140 $select->remove($handle) if !$bytes;
141 if ( $handle eq $reader ) {
142 $output_stream .= $buffer;
143 } elsif ( $handle eq $error ) {
144 $error_stream .= $buffer;
150 waitpid($pid, WNOHANG);
152 die "$error_stream" if length($error_stream);
154 return $output_stream;
158 =item sshopen2 [USER@]HOST, READER, WRITER, COMMAND [, ARGS ... ]
160 Connects the supplied filehandles to the ssh process (in batch mode).
165 my($host, $reader, $writer, @command) = @_;
166 @ssh_options = &_ssh_options unless @ssh_options;
167 open2($reader, $writer, $ssh, @ssh_options, $host, @command);
170 =item sshopen3 HOST, WRITER, READER, ERROR, COMMAND [, ARGS ... ]
172 Connects the supplied filehandles to the ssh process (in batch mode).
177 my($host, $writer, $reader, $error, @command) = @_;
178 @ssh_options = &_ssh_options unless @ssh_options;
179 open3($writer, $reader, $error, $ssh, @ssh_options, $host, @command);
183 print "Proceed [y/N]:";
184 my $x = scalar(<STDIN>);
189 my $reader = IO::File->new();
190 my $writer = IO::File->new();
191 my $error = IO::File->new();
192 open3($writer, $reader, $error, $ssh, '-V');
193 my $ssh_version = <$error>;
195 if ( $ssh_version =~ /.*OpenSSH[-|_](\w+)\./ && $1 == 1 ) {
200 my @options = ( '-o', 'BatchMode'.$equalspace.'yes' );
201 if ( $ssh_version =~ /.*OpenSSH[-|_](\w+)\./ && $1 > 1 ) {
202 unshift @options, '-T';
211 use Net::SSH qw(sshopen2);
214 my $user = "username";
215 my $host = "hostname";
218 sshopen2("$user\@$host", *READER, *WRITER, "$cmd") || die "ssh: $!";
228 =head1 FREQUENTLY ASKED QUESTIONS
230 Q: How do you supply a password to connect with ssh within a perl script
231 using the Net::SSH module?
233 A: You don't (at least not with this module). Use RSA or DSA keys. See the
234 quick help in the next section and the ssh-keygen(1) manpage.
236 A #2: See L<Net::SSH::Expect> instead.
238 Q: My script is "leaking" ssh processes.
240 A: See L<perlfaq8/"How do I avoid zombies on a Unix system">, L<IPC::Open2>,
241 L<IPC::Open3> and L<perlfunc/waitpid>.
243 =head1 GENERATING AND USING SSH KEYS
247 =item 1 Generate keys
253 And do not enter a passphrase unless you wanted to be prompted for
254 one during file copying.
256 Here is what you will see:
259 Generating public/private rsa key pair.
260 Enter file in which to save the key (/home/User/.ssh/id_rsa):
261 Enter passphrase (empty for no passphrase):
263 Enter same passphrase again:
265 Your identification has been saved in /home/User/.ssh/id_rsa.
266 Your public key has been saved in /home/User/.ssh/id_rsa.pub.
267 The key fingerprint is:
268 5a:cd:2b:0a:cd:d9:15:85:26:79:40:0c:55:2a:f4:23 User@JEFF-CPU
271 =item 2 Copy public to machines you want to upload to
273 C<id_rsa.pub> is your public key. Copy it to C<~/.ssh> on target machine.
275 Put a copy of the public key file on each machine you want to log into.
276 Name the copy C<authorized_keys> (some implementations name this file
281 chmod 600 authorized_keys
283 Then make sure your home dir on the remote machine is not group or
290 Ivan Kohler <ivan-netssh_pod@420.am>
292 Assistance wanted - this module could really use a maintainer with enough time
293 to at least review and apply more patches. Or the module should just be
294 deprecated in favor of Net::SSH::Expect or made into an ::Any style
295 compatibility wrapper that uses whatver implementation is avaialble
296 (Net::SSH2, Net::SSH::Perl or shelling out like the module does now). Please
297 email Ivan if you are interested in helping.
299 John Harrison <japh@in-ta.net> contributed an example for the documentation.
301 Martin Langhoff <martin@cwa.co.nz> contributed the ssh_cmd command, and
302 Jeff Finucane <jeff@cmh.net> updated it and took care of the 0.04 release.
304 Anthony Awtrey <tony@awtrey.com> contributed a fix for those still using
307 Thanks to terrence brannon <tbone@directsynergy.com> for the documentation in
308 the GENERATING AND USING SSH KEYS section.
312 Copyright (c) 2004 Ivan Kohler.
313 Copyright (c) 2007-2008 Freeside Internet Services, Inc.
315 This program is free software; you can redistribute it and/or modify it under
316 the same terms as Perl itself.
322 Look at IPC::Session (also fsh, well now the native SSH "master mode" stuff)
326 For a perl implementation that does not require the system B<ssh> command, see
327 L<Net::SSH::Perl> instead.
329 For a wrapper version that allows you to use passwords, see L<Net::SSH::Expect>
332 For another non-forking version that uses the libssh2 library, see
335 For a way to execute remote Perl code over an ssh connection see
338 ssh-keygen(1), ssh(1), L<IO::File>, L<IPC::Open2>, L<IPC::Open3>