Excuse me if I am misunderstanding something - but it certainly looks to me like you are not at any point closing the bufio.Writer (because it is not a WriteCloser and does not support Close function). That is why you need to flush it! What you are closing is the underlying file/stream/WriteCloser, but it is the bufio.Writer that has the data in its buffer, *not* the file. This is not the same thing as flushing a file descriptor, which happens on close.
"After all data has been written, the client should call the Flush method to guarantee all data has been forwarded to the underlying io.Writer." IF the bufio.Writer had been implemented as a WriteCloser, then closing it would probably flush as well - here is a discussion where they talk about how that could be implemented: https://stackoverflow.com/questions/43115699/how-to-get-a-bufio-writer-that-implements-io-writecloser Howard On Tuesday, May 21, 2019 at 8:42:51 AM UTC-5, Subramanian Sridharan wrote: > > I don't think so. > > When I close the file and don't explicitly flush: > > package main > > import ( > "bufio" > "fmt" > "io" > "os" > ) > > func main() { > sourceFilename := "MozillaFirefox-66.0.5-741.4.x86_64.rpm" > sourcef, err := os.Open(sourceFilename) > if err != nil { > fmt.Println("Error while opening source file:", err) > return > } > defer sourcef.Close() > > destinationFilename := "CopiedMozillaFirefox-66.0.5-741.4.x86_64.rpm" > os.Create(destinationFilename) > destf, err := os.OpenFile(destinationFilename, os.O_APPEND|os.O_WRONLY, > os.ModeAppend) > if err != nil { > fmt.Println("Error while opening destination file:", err) > return > } > defer func() { > fmt.Println("Closing file.") > destf.Close() > }() > > fReader := bufio.NewReader(sourcef) > fWriter := bufio.NewWriter(destf) > > n, err := io.Copy(fWriter, fReader) > if err != nil { > fmt.Println("Error while copying:", err) > return > } > > fmt.Println("Copied", n, "bytes.") > } > > >> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/24d5242a-3e5a-4b83-a6f2-1ca7e29cfe0e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
