Edit file File name : SSH.pm Content :package Net::SSH; use strict; use vars qw($VERSION @ISA @EXPORT_OK $ssh $equalspace $DEBUG @ssh_options); use Exporter; use POSIX ":sys_wait_h"; use IO::File; use IO::Select; use IPC::Open2; use IPC::Open3; @ISA = qw(Exporter); @EXPORT_OK = qw( ssh issh ssh_cmd sshopen2 sshopen3 ); $VERSION = '0.09'; $DEBUG = 0; $ssh = "ssh"; =head1 NAME Net::SSH - Perl extension for secure shell =head1 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, $command); =head1 DESCRIPTION Simple wrappers around ssh commands. For an all-perl implementation that does not require the system B<ssh> command, see L<Net::SSH::Perl> instead. =head1 SUBROUTINES =over 4 =item ssh [USER@]HOST, COMMAND [, ARGS ... ] Calls ssh in batch mode. =cut sub ssh { my($host, @command) = @_; @ssh_options = &_ssh_options unless @ssh_options; my @cmd = ($ssh, @ssh_options, $host, @command); warn "[Net::SSH::ssh] executing ". join(' ', @cmd). "\n" if $DEBUG; system(@cmd); } =item issh [USER@]HOST, COMMAND [, ARGS ... ] Prints the ssh command to be executed, waits for the user to confirm, and (optionally) executes the command. =cut sub issh { my($host, @command) = @_; my @cmd = ($ssh, $host, @command); print join(' ', @cmd), "\n"; if ( &_yesno ) { system(@cmd); } } =item ssh_cmd [USER@]HOST, COMMAND [, ARGS ... ] =item ssh_cmd OPTIONS_HASHREF Calls ssh in batch mode. Throws a fatal error if data occurs on the command's STDERR. Returns any data from the command's STDOUT. If using the hashref-style of passing arguments, possible keys are: user (optional) host (required) command (required) args (optional, arrayref) stdin_string (optional) - written to the command's STDIN =cut sub ssh_cmd { my($host, $stdin_string, @command); if ( ref($_[0]) ) { my $opt = shift; $host = $opt->{host}; $host = $opt->{user}. '@'. $host if exists $opt->{user}; @command = ( $opt->{command} ); push @command, @{ $opt->{args} } if exists $opt->{args}; $stdin_string = $opt->{stdin_string}; } else { ($host, @command) = @_; undef $stdin_string; } my $reader = IO::File->new(); my $writer = IO::File->new(); my $error = IO::File->new(); my $pid = sshopen3( $host, $writer, $reader, $error, @command ) or die $!; print $writer $stdin_string if defined $stdin_string; close $writer; my $select = new IO::Select; foreach ( $reader, $error ) { $select->add($_); } my($output_stream, $error_stream) = ('', ''); while ( $select->count ) { my @handles = $select->can_read; foreach my $handle ( @handles ) { my $buffer = ''; my $bytes = sysread($handle, $buffer, 4096); if ( !defined($bytes) ) { waitpid($pid, WNOHANG); die "[Net::SSH::ssh_cmd] $!" }; $select->remove($handle) if !$bytes; if ( $handle eq $reader ) { $output_stream .= $buffer; } elsif ( $handle eq $error ) { $error_stream .= $buffer; } } } waitpid($pid, WNOHANG); die "$error_stream" if length($error_stream); return $output_stream; } =item sshopen2 [USER@]HOST, READER, WRITER, COMMAND [, ARGS ... ] Connects the supplied filehandles to the ssh process (in batch mode). =cut sub sshopen2 { my($host, $reader, $writer, @command) = @_; @ssh_options = &_ssh_options unless @ssh_options; open2($reader, $writer, $ssh, @ssh_options, $host, @command); } =item sshopen3 HOST, WRITER, READER, ERROR, COMMAND [, ARGS ... ] Connects the supplied filehandles to the ssh process (in batch mode). =cut sub sshopen3 { my($host, $writer, $reader, $error, @command) = @_; @ssh_options = &_ssh_options unless @ssh_options; open3($writer, $reader, $error, $ssh, @ssh_options, $host, @command); } sub _yesno { print "Proceed [y/N]:"; my $x = scalar(<STDIN>); $x =~ /^y/i; } sub _ssh_options { my $reader = IO::File->new(); my $writer = IO::File->new(); my $error = IO::File->new(); open3($writer, $reader, $error, $ssh, '-V'); my $ssh_version = <$error>; chomp($ssh_version); if ( $ssh_version =~ /.*OpenSSH[-|_](\w+)\./ && $1 == 1 ) { $equalspace = " "; } else { $equalspace = "="; } my @options = ( '-o', 'BatchMode'.$equalspace.'yes' ); if ( $ssh_version =~ /.*OpenSSH[-|_](\w+)\./ && $1 > 1 ) { unshift @options, '-T'; } @options; } =back =head1 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); =head1 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 L<Net::SSH::Expect> instead. Q: My script is "leaking" ssh processes. A: See L<perlfaq8/"How do I avoid zombies on a Unix system">, L<IPC::Open2>, L<IPC::Open3> and L<perlfunc/waitpid>. =head1 GENERATING AND USING SSH KEYS =over 4 =item 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 =item 2 Copy public to machines you want to upload to C<id_rsa.pub> is your public key. Copy it to C<~/.ssh> on target machine. Put a copy of the public key file on each machine you want to log into. Name the copy C<authorized_keys> (some implementations name this file C<authorized_keys2>) Then type: chmod 600 authorized_keys Then make sure your home dir on the remote machine is not group or world writeable. =back =head1 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. =head1 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. =head1 BUGS Not OO. Look at IPC::Session (also fsh, well now the native SSH "master mode" stuff) =head1 SEE ALSO For a perl implementation that does not require the system B<ssh> command, see L<Net::SSH::Perl> instead. For a wrapper version that allows you to use passwords, see L<Net::SSH::Expect> instead. For another non-forking version that uses the libssh2 library, see L<Net::SSH2>. For a way to execute remote Perl code over an ssh connection see L<IPC::PerlSSH>. ssh-keygen(1), ssh(1), L<IO::File>, L<IPC::Open2>, L<IPC::Open3> =cut 1; Save