C++

Read Text at a String Offset from a Remote SFTP File

Demonstrates the Chilkat SFtp.ReadFileText64s method, which is like ReadFileText64 but takes the byte offset as a decimal string. The arguments are the handle, the offset string, the maximum number of bytes, and the charset.

Background: The string-offset read exists for the same reason as its write counterpart: it lets code in languages without convenient 64-bit integers still address positions in very large files by supplying the offset as text. Functionally it is identical to the int64 version.

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C++

#include <CkSFtp.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the SFtp.ReadFileText64s method, which is like ReadFileText64 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 maximum number of bytes, and the 4th is the charset.

    CkSFtp sftp;

    //  Connect, authenticate, and initialize the SFTP subsystem.
    int port = 22;
    success = sftp.Connect("sftp.example.com",port);
    if (success == false) {
        std::cout << sftp.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 = sftp.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        std::cout << sftp.lastErrorText() << "\r\n";
        return;
    }

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

    const char *handle = sftp.openFile("subdir/hugefile.dat","readOnly","openExisting");
    if (sftp.get_LastMethodSuccess() == false) {
        std::cout << sftp.lastErrorText() << "\r\n";
        return;
    }

    //  Supplying the offset as a string is convenient in languages without a native 64-bit integer.
    const char *offset = "5000000000";
    int numBytes = 6;
    const char *text = sftp.readFileText64s(handle,offset,numBytes,"utf-8");
    if (sftp.get_LastMethodSuccess() == false) {
        std::cout << sftp.lastErrorText() << "\r\n";
        return;
    }

    std::cout << text << "\r\n";

    success = sftp.CloseHandle(handle);
    if (success == false) {
        std::cout << sftp.lastErrorText() << "\r\n";
        return;
    }

    sftp.Disconnect();
    }