Check Whether the Last SFTP Read Failed

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Demonstrates the Chilkat SFtp.LastReadFailed method, which returns whether the most recent read for a handle failed. The only argument is the handle. A normal end-of-file is not a failure.

Background: A chunked read loop needs to tell three outcomes apart: more data, a clean end-of-file, and an actual error such as a dropped connection or a revoked handle. LastReadFailed isolates the error case — it is false on a normal EOF read (which succeeds with zero bytes) and true for an empty, malformed, or already-closed handle — so the loop can stop cleanly on EOF but bail out with an error message on a genuine failure.

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    success := false

    //  Demonstrates the SFtp.LastReadFailed method, which returns whether the most recent read for a
    //  handle failed.  The only argument is the handle.  A normal end-of-file is NOT a failure.

    sftp := chilkat.NewSFtp()

    //  Connect, authenticate, and initialize the SFTP subsystem.
    port := 22
    success = sftp.Connect("sftp.example.com",port)
    if success == false {
        fmt.Println(sftp.LastErrorText())
        sftp.DisposeSFtp()
        return
    }

    //  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.
    password := "mySshPassword"

    success = sftp.AuthenticatePw("mySshLogin",password)
    if success == false {
        fmt.Println(sftp.LastErrorText())
        sftp.DisposeSFtp()
        return
    }

    success = sftp.InitializeSftp()
    if success == false {
        fmt.Println(sftp.LastErrorText())
        sftp.DisposeSFtp()
        return
    }

    handle := sftp.OpenFile("subdir/data.txt","readOnly","openExisting")
    if sftp.LastMethodSuccess() == false {
        fmt.Println(sftp.LastErrorText())
        sftp.DisposeSFtp()
        return
    }

    reading := true
    chunkSize := 4096
    bd := chilkat.NewBinData()
    for reading {
        success = sftp.ReadFileBd(*handle,chunkSize,bd)

        //  Distinguish an actual read failure from a normal EOF.  On EOF the read succeeds, returns
        //  zero bytes, and LastReadFailed is false.
        if sftp.LastReadFailed(*handle) {
            fmt.Println("Read failed: ", sftp.LastErrorText())
            sftp.DisposeSFtp()
            bd.DisposeBinData()
            return
        }

        reading = !sftp.Eof(*handle)
    }

    success = sftp.CloseHandle(*handle)
    if success == false {
        fmt.Println(sftp.LastErrorText())
        sftp.DisposeSFtp()
        bd.DisposeBinData()
        return
    }

    fmt.Println("Read ", bd.NumBytes(), " bytes with no read failures.")

    sftp.Disconnect()

    sftp.DisposeSFtp()
    bd.DisposeBinData()