Unicode C++

Check Whether an SSH Exit Status Was Received

Demonstrates the Chilkat Ssh.ChannelReceivedExitStatus method, which reports whether the server supplied an exit-status value for a channel. The only argument is the channel number. When it returns true, call GetChannelExitStatus to read the value.

Background: Always test this before reading the exit status, because the server is not required to send one for every channel type or command — treating a missing status as "0" would silently turn a failure into a success. Exit status is independent of EOF and CLOSE: it can arrive after EOF and either before or together with CLOSE.

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#include <CkSshW.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the Ssh.ChannelReceivedExitStatus method, which reports whether the server
    //  supplied an exit-status value for a channel.  The only argument is the channel number.  When
    //  it returns true, call GetChannelExitStatus to read the value.

    CkSshW ssh;

    int sshPort = 22;
    success = ssh.Connect(L"ssh.example.com",sshPort);
    if (success == false) {
        wprintf(L"%s\n",ssh.lastErrorText());
        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 wchar_t *password = L"mySshPassword";

    success = ssh.AuthenticatePw(L"mySshLogin",password);
    if (success == false) {
        wprintf(L"%s\n",ssh.lastErrorText());
        return;
    }

    int channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        wprintf(L"%s\n",ssh.lastErrorText());
        return;
    }

    success = ssh.SendReqExec(channelNum,L"test -f /etc/hosts");
    if (success == false) {
        wprintf(L"%s\n",ssh.lastErrorText());
        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) {
        wprintf(L"%s\n",ssh.lastErrorText());
        return;
    }

    //  The server is not required to send an exit status for every channel type or command.
    if (ssh.ChannelReceivedExitStatus(channelNum)) {
        int exitStatus = ssh.GetChannelExitStatus(channelNum);
        wprintf(L"Exit status: %d\n",exitStatus);
    }
    else {
        wprintf(L"The server did not provide an exit status.\n");
    }

    ssh.Disconnect();
    }