Visual FoxPro

Run a Command on an SSH Session Channel

Demonstrates the Chilkat Ssh.SendReqExec method, which requests execution of a command on a session channel. The first argument is the channel number and the second is the command line. This example runs a command, reads the output until the channel closes, and prints it.

Background: exec is the workhorse for automation: run one command, collect its output, and finish — no interactive shell needed. Note carefully that a true return means the request was accepted, not that the command succeeded. To learn the command's outcome, read its output and check the channel exit status.

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LOCAL lnSuccess
LOCAL loSsh
LOCAL lnSshPort
LOCAL lcPassword
LOCAL lnChannelNum
LOCAL lcOutput

lnSuccess = 0

*  Demonstrates the Ssh.SendReqExec method, which requests execution of a command on a session
*  channel.  The 1st argument is the channel number and the 2nd is the command line.

loSsh = CreateObject('Chilkat.Ssh')

lnSshPort = 22
lnSuccess = loSsh.Connect("ssh.example.com",lnSshPort)
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  Normally you would not hard-code the password in source.  You should instead obtain it
*  from an interactive prompt, environment variable, or a secrets vault.
lcPassword = "mySshPassword"

lnSuccess = loSsh.AuthenticatePw("mySshLogin",lcPassword)
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  Open a session channel.  A negative return value indicates failure.
lnChannelNum = loSsh.OpenSessionChannel()
IF (lnChannelNum < 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  Request execution of a command.  A 1 return means the server accepted the request; it
*  does not mean the command itself succeeded.
lnSuccess = loSsh.SendReqExec(lnChannelNum,"ls -l /tmp")
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  IMPORTANT: Set a read timeout.  ReadTimeoutMs defaults to 0, which means no limit -- without
*  it, this call waits forever if the server never sends channel close.
loSsh.ReadTimeoutMs = 15000

*  Read the command output until the server closes the channel.
lnSuccess = loSsh.ChannelReceiveToClose(lnChannelNum)
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

lcOutput = loSsh.GetReceivedText(lnChannelNum,"utf-8")
IF (loSsh.LastMethodSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

? lcOutput

loSsh.Disconnect()

RELEASE loSsh