Upload a Large File in Chunks (FTP)

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Demonstrates the Chilkat Ftp2.LargeFileUpload method, which uploads a local file as a sequence of transfers, each up to a given chunk size. The arguments are the local path, the remote path, and the chunk size in bytes.

Note: The local paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Some servers, proxies, or firewalls impose a limit on the size or duration of a single data transfer, which a very large file can exceed. This method sidesteps that by sending the file in pieces — the first with STOR to create or replace the file, each subsequent one appended — so no single transfer is oversized. Choose a chunk size comfortably under whatever limit you are working around.

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bool success = false;

//  Demonstrates the Ftp2.LargeFileUpload method, which uploads a local file as a sequence of
//  transfers, each up to a given chunk size.  The 1st argument is the local path, the 2nd is the
//  remote path, and the 3rd is the chunk size in bytes.

Chilkat.Ftp2 ftp = new Chilkat.Ftp2();

ftp.Hostname = "ftp.example.com";
ftp.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.Password = "myPassword";

success = ftp.Connect();
if (success == false) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

//  The first chunk is sent with STOR (creating/replacing the remote file); each later chunk is
//  appended.  Uploading in chunks can work around server or network limits on a single transfer.
int chunkSize = 10485760;
success = ftp.LargeFileUpload("qa_data/bigfile.zip","uploads/bigfile.zip",chunkSize);
if (success == false) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

Debug.WriteLine("Large file uploaded.");

success = ftp.Disconnect();
if (success == false) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}