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C

Write Text at a String Offset in a Remote SFTP File

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Demonstrates the Chilkat SFtp.WriteFileText64s method, which is like WriteFileText64 but takes the byte offset as a decimal string. The arguments are the handle, the offset string, the charset, and the text.

Background: Some programming languages Chilkat targets lack a native 64-bit integer type, or make large integer literals awkward. Passing the offset as a decimal string sidesteps that entirely — the value is parsed by the library — while addressing the same large-file positions as the int64 form.

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C
#include <C_CkSFtp.h>

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

    success = FALSE;

    //  Demonstrates the SFtp.WriteFileText64s method, which is like WriteFileText64 but takes the
    //  byte offset as a decimal string.  The 1st argument is the handle, the 2nd is the offset string,
    //  the 3rd is the charset, and the 4th is the text.

    sftp = CkSFtp_Create();

    //  Connect, authenticate, and initialize the SFTP subsystem.
    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;
    }

    success = CkSFtp_InitializeSftp(sftp);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    handle = CkSFtp_openFile(sftp,"subdir/hugefile.dat","readWrite","openOrCreate");
    if (CkSFtp_getLastMethodSuccess(sftp) == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    //  Supplying the offset as a string is convenient in languages without a native 64-bit integer.
    offset = "5000000000";
    success = CkSFtp_WriteFileText64s(sftp,handle,offset,"utf-8","MARKER");
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    success = CkSFtp_CloseHandle(sftp,handle);
    if (success == FALSE) {
        printf("%s\n",CkSFtp_lastErrorText(sftp));
        CkSFtp_Dispose(sftp);
        return;
    }

    printf("Wrote at the string offset.\n");

    CkSFtp_Disconnect(sftp);


    CkSFtp_Dispose(sftp);

    }