Multiple SendReqExec on the Same Connection

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Demonstrates running a series of commands on one SSH connection using SendReqExec. Each exec request requires its own logical channel — this is not a separate SSH connection, just a new session channel on the existing one.

Background: An SSH session channel is single-use for an exec request: once the command runs and the server closes the channel, that channel cannot be reused. Opening a fresh channel per command is cheap, since the expensive work — the TCP connection, key exchange, and authentication — is done once and shared. This is why running ten commands over one connection is far faster than connecting ten times.

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    success := false

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

    //  Demonstrates running a series of commands on one SSH connection using SendReqExec.  Each exec
    //  request requires its own logical channel.  This is not a new SSH connection -- it is simply a
    //  new session channel on the existing one.

    ssh := chilkat.NewSsh()

    hostname := "ssh.example.com"
    port := 22
    success = ssh.Connect(hostname,port)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    //  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.
    password := "mySshPassword"

    success = ssh.AuthenticatePw("mySshLogin",password)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    //  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.
    ssh.SetReadTimeoutMs(15000)

    //  ---- 1st command, on its own session channel ----
    channelNum := ssh.OpenSessionChannel()
    if channelNum < 0 {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    success = ssh.SendReqExec(channelNum,"ls -al")
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    success = ssh.ChannelReceiveToClose(channelNum)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    cmdOutput := ssh.GetReceivedText(channelNum,"utf-8")
    if ssh.LastMethodSuccess() == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    fmt.Println(*cmdOutput)
    fmt.Println("----")

    //  ---- 2nd command, on a NEW session channel over the same connection ----
    channelNum = ssh.OpenSessionChannel()
    if channelNum < 0 {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    success = ssh.SendReqExec(channelNum,"nslookup chilkatsoft.com")
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    success = ssh.ChannelReceiveToClose(channelNum)
    if success == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    cmdOutput = ssh.GetReceivedText(channelNum,"utf-8")
    if ssh.LastMethodSuccess() == false {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    fmt.Println(*cmdOutput)

    ssh.Disconnect()

    ssh.DisposeSsh()