SSH Remote Shell

Demonstrates how to start a shell on a remote SSH server, run a command, and retrieve the output.

 Chilkat Perl Module Downloads for Windows, Linux, and MAC OS X

use chilkat();

#  Important: It is helpful to send the contents of the
#  ssh.LastErrorText property when requesting support.

$ssh = new chilkat::CkSsh();

#  Any string automatically begins a fully-functional 30-day trial.
$success = $ssh->UnlockComponent("30-day trial");
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Connect to an SSH server:

#  Hostname may be an IP address or hostname:
$hostname = "www.some-ssh-server.com";
$port = 22;

$success = $ssh->Connect($hostname,$port);
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Wait a max of 5 seconds when reading responses..
$ssh->put_IdleTimeoutMs(5000);

#  Authenticate using login/password:
$success = $ssh->AuthenticatePw("myLogin","myPassword");
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Open a session channel.  (It is possible to have multiple
#  session channels open simultaneously.)

$channelNum = $ssh->OpenSessionChannel();
if ($channelNum < 0) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Some SSH servers require a pseudo-terminal
#  If so, include the call to SendReqPty.  If not, then
#  comment out the call to SendReqPty.
#  Note: The 2nd argument of SendReqPty is the terminal type,
#  which should be something like "xterm", "vt100", "dumb", etc.
#  A "dumb" terminal is one that cannot process escape sequences.
#  Smart terminals, such as "xterm", "vt100", etc. process
#  escape sequences.  If you select a type of smart terminal,
#  your application will receive these escape sequences
#  included in the command's output.  Use "dumb" if you do not
#  want to receive escape sequences.  (Assuming your SSH
#  server recognizes "dumb" as a standard dumb terminal.)
$termType = "dumb";
$widthInChars = 120;
$heightInChars = 40;
#  Use 0 for pixWidth and pixHeight when the dimensions
#  are set in number-of-chars.
$pixWidth = 0;
$pixHeight = 0;
$success = $ssh->SendReqPty($channelNum,$termType,$widthInChars,$heightInChars,$pixWidth,$pixHeight);
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Start a shell on the channel:
$success = $ssh->SendReqShell($channelNum);
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Start a command in the remote shell.  This example
#  will send a "dir" command to retrieve the directory listing.
$success = $ssh->ChannelSendString($channelNum,"dir" . "\r\n","ansi");
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Send an EOF.  This tells the server that no more data will
#  be sent on this channel.  The channel remains open, and
#  the SSH client may still receive output on this channel.
$success = $ssh->ChannelSendEof($channelNum);
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Read whatever output may already be available on the
#  SSH connection.  ChannelReadAndPoll returns the number of bytes
#  that are available in the channel's internal buffer that
#  are ready to be "picked up" by calling GetReceivedText
#  or GetReceivedData.
#  A return value of -1 indicates failure.
#  A return value of -2 indicates a failure via timeout.

#  The ChannelReadAndPoll method waits
#  for data to arrive on the connection usingi the IdleTimeoutMs
#  property setting.  Once the first data arrives, it continues
#  reading but instead uses the pollTimeoutMs passed in the 2nd argument:
#  A return value of -2 indicates a timeout where no data is received.

$pollTimeoutMs = 2000;
$n = $ssh->ChannelReadAndPoll($channelNum,$pollTimeoutMs);
if ($n < 0) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Close the channel:
$success = $ssh->ChannelSendClose($channelNum);
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Perhaps we did not receive all of the commands output.
#  To make sure,  call ChannelReceiveToClose to accumulate any remaining
#  output until the server's corresponding "channel close" is received.
$success = $ssh->ChannelReceiveToClose($channelNum);
if ($success != 1) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Let's pickup the accumulated output of the command:

$cmdOutput = $ssh->getReceivedText($channelNum,"ansi");
if ($cmdOutput eq null ) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

#  Display the remote shell's command output:
print $cmdOutput . "\r\n";

#  Disconnect
$ssh->Disconnect();