(PureBasic) Multiple SendReqExec on Same Connection

Shows how to execute a series of commands on an SSH server and retrieve each command's output (using SendReqExec). Each call to SendReqExec requires its own logical channel. This is not a separate SSH connection -- it's simply a new session channel on the existing SSH connection.

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IncludeFile "CkSsh.pb"

Procedure ChilkatExample()

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

    ssh.i = CkSsh::ckCreate()
    If ssh.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Hostname may be an IP address or domain:
    hostname.s = "172.16.16.46"
    port.i = 22

    success.i = CkSsh::ckConnect(ssh,hostname,port)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; If receiving output from a command stalls for more than 5 seconds, then stop waiting.
    CkSsh::setCkIdleTimeoutMs(ssh, 5000)

    ; Authenticate using login/password:
    success = CkSsh::ckAuthenticatePw(ssh,"myLogin","myPassword")
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; Open a session channel.  (It is possible to have multiple
    ; session channels open simultaneously.)
    channelNum.i = CkSsh::ckOpenSessionChannel(ssh)
    If channelNum < 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; Request a directory listing on the remote server:
    ; If your server is Linux/UNIX, change the string from "dir" to "ls"
    ; Note: Some SSH servers require a CRLF instead of a bare-LF
    cmd.s = "ls -al" + Chr(10)
    success = CkSsh::ckSendReqExec(ssh,channelNum,cmd)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    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.
    pollTimeoutMs.i = 2000
    n.i = CkSsh::ckChannelReadAndPoll(ssh,channelNum,pollTimeoutMs)
    If n < 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; Close the channel:
    success = CkSsh::ckChannelSendClose(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    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.
    success = CkSsh::ckChannelReceiveToClose(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; Get the accumulated output of the command:
    cmdOutput.s
    cmdOutput = CkSsh::ckGetReceivedText(ssh,channelNum,"ansi")
    If CkSsh::ckLastMethodSuccess(ssh) = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; Display the remote shell's command output:
    Debug cmdOutput
    Debug "----"

    ; -----------------------------------------------------------------
    ; Now for the 2nd SendReqExe (on the same connection,
    ; but on a separate logical channel).
    ; -----------------------------------------------------------------

    channelNum = CkSsh::ckOpenSessionChannel(ssh)
    If channelNum < 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    cmd = "nslookup chilkatsoft.com" + Chr(10)
    success = CkSsh::ckSendReqExec(ssh,channelNum,cmd)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    pollTimeoutMs = 2000
    n = CkSsh::ckChannelReadAndPoll(ssh,channelNum,pollTimeoutMs)
    If n < 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    success = CkSsh::ckChannelSendClose(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    success = CkSsh::ckChannelReceiveToClose(ssh,channelNum)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    cmdOutput = CkSsh::ckGetReceivedText(ssh,channelNum,"ansi")
    If CkSsh::ckLastMethodSuccess(ssh) = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    Debug cmdOutput


    CkSsh::ckDispose(ssh)


    ProcedureReturn
EndProcedure