Xbase++

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.

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LOCAL nSuccess
LOCAL oFtp

nSuccess := 0

oFtp := CreateObject("Chilkat.Ftp2")

oFtp:Hostname := "ftp.example.com"
oFtp: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.
oFtp:Password := "myPassword"

nSuccess := oFtp:Connect()
IF (nSuccess == 0)
    ? oFtp:LastErrorText
    oFtp:destroy()
    RETURN
ENDIF

//  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

nSuccess := oFtp:PutFile("qa_data/bigfile.zip", "uploads/bigfile.zip")
IF (nSuccess == 0)
    ? oFtp:LastErrorText
    oFtp:destroy()
    RETURN
ENDIF

? "Uploaded with pre-allocation."

nSuccess := oFtp:Disconnect()
IF (nSuccess == 0)
    ? oFtp:LastErrorText
    oFtp:destroy()
    RETURN
ENDIF

oFtp:destroy()