SSH Remote Shell

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

Download Chilkat SSH / SFTP ActiveX

LOCAL loSsh
LOCAL lnSuccess
LOCAL lcHostname
LOCAL lnPort
LOCAL lnChannelNum
LOCAL lcTermType
LOCAL lnWidthInChars
LOCAL lnHeightInChars
LOCAL lnPixWidth
LOCAL lnPixHeight
LOCAL n
LOCAL lnPollTimeoutMs
LOCAL lcCmdOutput

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

loSsh = CreateObject('Chilkat.Ssh')

*  Any string automatically begins a fully-functional 30-day trial.

lnSuccess = loSsh.UnlockComponent("30-day trial")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  Connect to an SSH server:

*  Hostname may be an IP address or hostname:
lcHostname = "www.some-ssh-server.com"
lnPort = 22

lnSuccess = loSsh.Connect(lcHostname,lnPort)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  Wait a max of 5 seconds when reading responses..
loSsh.IdleTimeoutMs = 5000

*  Authenticate using login/password:
lnSuccess = loSsh.AuthenticatePw("myLogin","myPassword")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

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

lnChannelNum = loSsh.OpenSessionChannel()
IF (lnChannelNum < 0) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  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.)

lcTermType = "dumb"

lnWidthInChars = 120

lnHeightInChars = 40
*  Use 0 for pixWidth and pixHeight when the dimensions
*  are set in number-of-chars.

lnPixWidth = 0

lnPixHeight = 0
lnSuccess = loSsh.SendReqPty(lnChannelNum,lcTermType,lnWidthInChars,lnHeightInChars,lnPixWidth,lnPixHeight)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  Start a shell on the channel:
lnSuccess = loSsh.SendReqShell(lnChannelNum)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  Start a command in the remote shell.  This example
*  will send a "dir" command to retrieve the directory listing.
lnSuccess = loSsh.ChannelSendString(lnChannelNum,"dir" + CHR(13)+CHR(10),"ansi")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  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.
lnSuccess = loSsh.ChannelSendEof(lnChannelNum)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  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.

lnPollTimeoutMs = 2000
n = loSsh.ChannelReadAndPoll(lnChannelNum,lnPollTimeoutMs)
IF (n < 0) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  Close the channel:
lnSuccess = loSsh.ChannelSendClose(lnChannelNum)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  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.
lnSuccess = loSsh.ChannelReceiveToClose(lnChannelNum)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

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

lcCmdOutput = loSsh.GetReceivedText(lnChannelNum,"ansi")
IF (lcCmdOutput = NULL ) THEN
    =MESSAGEBOX(loSsh.LastErrorText)
    QUIT
ENDIF

*  Display the remote shell's command output:
? lcCmdOutput

*  Disconnect
loSsh.Disconnect()