C++

Pre-Allocate Server Space Before an FTP Upload (ALLO)

Demonstrates the AllocateSize property, which sends the FTP ALLO command to pre-allocate disk space on the server before an upload. Set it to the size in bytes of the file about to be uploaded.

Background: ALLO asks the server to reserve storage in advance, a requirement of certain legacy systems — older mainframes in particular — that need the exact file size up front to allocate a dataset. Modern servers allocate space dynamically and typically ignore or accept ALLO without needing it, so most applications never set this. Provide it only when targeting a host known to require pre-allocation.

Chilkat C++ Downloads

Download Chilkat for C++

C++

#include <CkFtp2.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkFtp2 ftp;

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("myFtpLogin");

    //  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.
    ftp.put_Password("myPassword");

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

    //  AllocateSize sends the FTP ALLO command to pre-allocate disk space on the server before an
    //  upload.  It is rarely needed -- mainly for certain legacy systems that require the exact size
    //  in advance -- since most servers allocate space dynamically.  Set it to the size in bytes of
    //  the file about to be uploaded.
ERROR: Assignment type mismatch.  ExpressionType=int, atgType=uint

    success = ftp.PutFile("qa_data/bigfile.zip","uploads/bigfile.zip");
    if (success == false) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Uploaded with pre-allocation." << "\r\n";

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