(Ruby) SSH Remote Shell

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

Downloads for Windows/Linux and Install Instructions

require 'chilkat'

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

ssh = Chilkat::CkSsh.new()

#  Any string automatically begins a fully-functional 30-day trial.
success = ssh.UnlockComponent("30-day trial")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  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 != true)
    print ssh.lastErrorText() + "\n";
    exit
end

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

#  Authenticate using login/password:
success = ssh.AuthenticatePw("myLogin","myPassword")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  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
end

#  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 != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  Start a shell on the channel:
success = ssh.SendReqShell(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  Start a command in the remote shell.  This example
#  will send a "ls" command to retrieve the directory listing.
success = ssh.ChannelSendString(channelNum,"ls" + "\r\n","ansi")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  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 != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  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
end

#  Close the channel:
success = ssh.ChannelSendClose(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  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 != true)
    print ssh.lastErrorText() + "\n";
    exit
end

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

cmdOutput = ssh.getReceivedText(channelNum,"ansi")
if (cmdOutput == nil )
    print ssh.lastErrorText() + "\n";
    exit
end

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

#  Disconnect
ssh.Disconnect()