Xbase++

Enable FTP MODE Z Compression

Demonstrates the Chilkat Ftp2.SetModeZ method, which enables MODE Z compression for subsequent data connections. It takes no arguments. Call it after connecting and only when the HasModeZ property is true.

Background: MODE Z compresses data on the fly (using zlib) as it crosses the wire, which can meaningfully speed up transfers of compressible content — text, HTML, logs — over a slow link. It is a server extension, so check HasModeZ first and expect it to be unavailable on many servers. There is little benefit for already-compressed data such as images or archives, where the CPU cost of compression buys almost nothing.

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LOCAL nSuccess
LOCAL oFtp

nSuccess := 0

//  Demonstrates the Ftp2.SetModeZ method, which enables MODE Z compression for subsequent data
//  connections.  It takes no arguments.  Call it after connecting, and only when the HasModeZ
//  property indicates the server supports it.

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

nSuccess := oFtp:ChangeRemoteDir("public_html")
IF (nSuccess == 0)
    ? oFtp:LastErrorText
    oFtp:destroy()
    RETURN
ENDIF

//  Only enable compression if the server advertises MODE Z support.
IF (oFtp:HasModeZ)
    nSuccess := oFtp:SetModeZ()
    IF (nSuccess == 0)
        ? oFtp:LastErrorText
        oFtp:destroy()
        RETURN
    ENDIF

    ? "MODE Z compression enabled."
ELSE
    ? "The server does not support MODE Z."
ENDIF

//  Subsequent uploads, downloads, and listings are transferred compressed.

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

oFtp:destroy()