DataFlex

Upload a Large File in Chunks (FTP)

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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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoFtp
    Integer iChunkSize
    String sTemp1

    Move False To iSuccess

    //  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.

    Get Create (RefClass(cComChilkatFtp2)) To hoFtp
    If (Not(IsComObjectCreated(hoFtp))) Begin
        Send CreateComObject of hoFtp
    End

    Set ComHostname Of hoFtp To "ftp.example.com"
    Set ComUsername Of hoFtp To "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.
    Set ComPassword Of hoFtp To "myPassword"

    Get ComConnect Of hoFtp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  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.
    Move 10485760 To iChunkSize
    Get ComLargeFileUpload Of hoFtp "qa_data/bigfile.zip" "uploads/bigfile.zip" iChunkSize To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Large file uploaded."

    Get ComDisconnect Of hoFtp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
        Procedure_Return
    End



End_Procedure