Xbase++

FTP Socket Buffer and Address Options

Demonstrates the SoRcvBuf, SoSndBuf, PreferIpv6, and ClientIpAddress properties.

Background: These are low-level knobs for specific situations. Larger send/receive buffers can improve throughput on high-bandwidth, high-latency links, though the defaults suit the common case. PreferIpv6 only matters when a hostname resolves to both address families, choosing which to try first. ClientIpAddress is normally left unset; set it on a multihomed host to bind the outgoing connection to a particular local interface. Change any of these only with a concrete reason.

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LOCAL nSuccess
LOCAL oFtp

nSuccess := 0

oFtp := CreateObject("Chilkat.Ftp2")

oFtp:Hostname := "ftp.example.com"
oFtp:Username := "myFtpLogin"

//  SoRcvBuf and SoSndBuf set the TCP socket receive/send buffer sizes.  The defaults are tuned for
//  the common case; larger values can sometimes help throughput on high-latency links.
oFtp:SoRcvBuf := 4194304
oFtp:SoSndBuf := 524288

//  PreferIpv6 (default 0) chooses IPv6 over IPv4 when a hostname resolves to both.
oFtp:PreferIpv6 := 0

//  ClientIpAddress is normally left unset; set it on a multihomed host to bind the outgoing
//  connection to a specific local interface.
oFtp:ClientIpAddress := "192.168.1.50"

//  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

? "Connected with custom socket options."

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

oFtp:destroy()