Send an SSH IGNORE Message over SFTP

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Demonstrates the Chilkat SFtp.SendIgnore method, which sends an SSH IGNORE message. It takes no arguments. The server sends no reply, but a successful send helps confirm the connection is still writable. No SFTP file handle is required.

Background: The SSH IGNORE message is discarded by the peer by design; its value is as a lightweight keep-alive or liveness probe. During a long-idle SFTP session — for instance while waiting between scheduled transfers — a periodic SendIgnore both keeps the connection from being dropped for inactivity and proves the link is still usable, without touching any file.

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#include <C_CkSFtp.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSFtp sftp;
    int port;
    const char *password;

    success = FALSE;

    //  Demonstrates the SFtp.SendIgnore method, which sends an SSH IGNORE message.  It takes no
    //  arguments.  The server sends no reply, but a successful send helps confirm the connection is
    //  still writable.  No SFTP file handle is required.

    sftp = CkSFtp_Create();

    //  Step 1: Connect the SSH transport.  Port 22 is the usual port.
    port = 22;
    success = CkSFtp_Connect(sftp,"sftp.example.com",port);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        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 = CkSFtp_AuthenticatePw(sftp,"mySshLogin",password);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    //  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
    //  file or directory operations.
    success = CkSFtp_InitializeSftp(sftp);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    //  Send an IGNORE message to verify the connection is still writable.
    success = CkSFtp_SendIgnore(sftp);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    printf("IGNORE message sent.\n");

    CkSFtp_Disconnect(sftp);


    CkSFtp_Dispose(sftp);

    }