C++

Get Received SSH Text into a StringBuilder

Demonstrates the Chilkat Ssh.GetReceivedSb method, which decodes a channel's receive buffer and appends the text to a StringBuilder. The arguments are the channel number, the charset, and the StringBuilder. The receive buffer is cleared afterward.

Background: Because this appends rather than replaces, it is the natural choice for accumulating output across repeated reads — call it in a loop and the StringBuilder grows into the complete transcript. It also avoids creating a new string on every retrieval, which matters when a command produces a large amount of text.

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C++

#include <CkSsh.h>
#include <CkStringBuilder.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the Ssh.GetReceivedSb method, which decodes the channel's receive buffer and
    //  appends the text to a StringBuilder.  The 1st argument is the channel number, the 2nd is the
    //  charset, and the 3rd is the StringBuilder.  The receive buffer is cleared afterward.

    CkSsh ssh;

    int sshPort = 22;
    success = ssh.Connect("ssh.example.com",sshPort);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        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.
    const char *password = "mySshPassword";

    success = ssh.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    int channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    success = ssh.SendReqExec(channelNum,"ls -l /tmp");
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        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.put_ReadTimeoutMs(15000);

    success = ssh.ChannelReceiveToClose(channelNum);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    //  Append the received text to a StringBuilder.  Existing content is preserved.
    CkStringBuilder sb;
    success = ssh.GetReceivedSb(channelNum,"utf-8",sb);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Characters received: " << sb.get_Length() << "\r\n";
    const char *output = sb.getAsString();
    std::cout << output << "\r\n";

    ssh.Disconnect();
    }