SSH Exec (Execute Command Line)

Shows how to execute a command on an SSH server and retrieve the command output.

Download Chilkat Ruby Library

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("Anything for 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 = "192.168.1.108"
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

#  The SendReqExec method starts a command on the remote
#  server.   The syntax of the command string depends on the
#  default shell used on the remote server to run the command.
#  On Windows systems it is CMD.EXE.  On UNIX/Linux
#  systems the user's default shell is typically defined in /etc/password.

#  Here are some examples of command lines for <b>Windows SSH servers</b>:

#  Get a directory listing:
cmd1 = "dir"

#  Do a nameserver lookup:
cmd2 = "nslookup chilkatsoft.com"

#  List a specific directory.  Given that the shell is CMD.EXE, backslashes must
#  be used:
cmd3 = "dir \\temp"

#  Execute a sequence of commands.  The syntax for CMD.EXE may be found
#  here: http://technet.microsoft.com/en-us/library/bb490880.aspx.  Notice how the commands
#  are separated by "##" and the entire command must be enclosed in quotes:
cmd4 = "\"cd \\temp&&dir\""

#  Here are two examples of command lines for <b>Linux/UNIX SSH servers</b>:

#  Get a directory listing:
cmd5 = "ls -l /tmp"

#  Run a series of commands (syntax may depend on your default shell):
cmd6 = "cd /etc; ls -la"

#  Request a directory listing on the remote server:
#  If your server is Linux/UNIX, change the string from "dir" to "ls"
success = ssh.SendReqExec(channelNum,"dir")
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()