DataFlex

FTP XCRC

See more FTP Examples

Demonstrates how to tell Chilkat FTP2 to automatically verify an upload using XCRC. XCRC is an FTP extension supported by most FTP servers. If your FTP server does not support XCRC, then no XCRC command will be sent to verify the upload.

The XCRC command asks the FTP server to send an CRC checksum (hash) for the contents of a file. The client can then verify that the checksum matches the local file. The FTP2 Put* methods automatically do this when the AutoXcrc property is turned on.

Note: In order for the FTP2 component to know whether XCRC is supported by your FTP server, you must have the AutoFeat property turned on (which is the default setting). The AutoFeat property tells the FTP2 component to automatically request the FTP server features via the FEAT command after connecting.

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoFtp
    String sLocalFilename
    String sRemoteFilename
    String sTemp1

    Move False To iSuccess

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    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 "login"
    Set ComPassword Of hoFtp To "password"

    // Turn on the AutoXcrc property:
    Set ComAutoXcrc Of hoFtp To True

    // Turn on session logging.  We'll want to examine it to
    // see the XCRC command:
    Set ComKeepSessionLog Of hoFtp To True

    // Connect and login to the FTP server.
    Get ComConnect Of hoFtp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Change to the remote directory where the file will be uploaded.
    Get ComChangeRemoteDir Of hoFtp "junk" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Upload a file.
    Move "hamlet.xml" To sLocalFilename
    Move "hamlet.xml" To sRemoteFilename

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

    // If we examine the session log, we'll see the XCRC command:
    Get ComSessionLog Of hoFtp To sTemp1
    Showln sTemp1

    Get ComDisconnect Of hoFtp To iSuccess

    Showln "File Uploaded!"

    // Here is the session log showing the XCRC command:

    // 220 Serv-U FTP Server v6.3 for WinSock ready...
    // .
    // USER example-code.com
    // 331 User name okay, need password.
    // .
    // PASS ****
    // 230 User logged in, proceed.
    // .
    // TYPE I
    // 200 Type set to I.
    // .
    // SYST
    // 215 UNIX Type: L8
    // .
    // FEAT
    // 211-Extension supported
    //  CLNT
    //  MDTM
    //  MDTM YYYYMMDDHHMMSS[+-TZ];filename
    //  SIZE
    //  SITE PSWD;EXEC;SET;INDEX;ZONE;CHMOD;MSG
    //  REST STREAM
    //  XCRC filename;start;end
    //  MODE Z
    //  MLST Type*;Size*;Create;Modify*;Win32.ea*;
    // 211 End
    // .
    // CWD junk
    // 250 Directory changed to /junk
    // .
    // PORT 192,168,1,103,5,144
    // 200 PORT Command successful.
    // .
    // STOR hamlet.xml
    // 150 Opening BINARY mode data connection for hamlet.xml.
    // 226 Transfer complete.
    // .
    // XCRC hamlet.xml
    // 250 3C1933B


End_Procedure