Lianja

SSH Remote Shell

See more SSH Examples

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

llSuccess = .F.

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

loSsh = createobject("CkSsh")

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

// Connect to an SSH server:
llSuccess = loSsh.Connect(lcHostname,lnPort)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

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

// Authenticate using login/password:
llSuccess = loSsh.AuthenticatePw("myLogin","myPassword")
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

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

lnChannelNum = loSsh.OpenSessionChannel()
if (lnChannelNum < 0) then
    ? loSsh.LastErrorText
    release loSsh
    return
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
llSuccess = loSsh.SendReqPty(lnChannelNum,lcTermType,lnWidthInChars,lnHeightInChars,lnPixWidth,lnPixHeight)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Start a shell on the channel:
llSuccess = loSsh.SendReqShell(lnChannelNum)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Start a command in the remote shell.  This example
// will send a "ls" command to retrieve the directory listing.
llSuccess = loSsh.ChannelSendString(lnChannelNum,"ls" + Chr(13) + Chr(10),"ansi")
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
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.
llSuccess = loSsh.ChannelSendEof(lnChannelNum)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
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
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Close the channel:
llSuccess = loSsh.ChannelSendClose(lnChannelNum)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
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.
llSuccess = loSsh.ChannelReceiveToClose(lnChannelNum)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Let's pickup the accumulated output of the command:
lcCmdOutput = loSsh.GetReceivedText(lnChannelNum,"ansi")
if (loSsh.LastMethodSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

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

// Disconnect
loSsh.Disconnect()


release loSsh