That’s what I was saying, I incorrectly thought that the Writer was a WriterCloser.
Seems it should be with a noop if the contained Writer is not a WriterCloser. This would be pretty much how every other platform does buffered IO. > On May 21, 2019, at 11:19 AM, howardcs...@gmail.com wrote: > > 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. -- 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/D61080CC-6271-4782-88A8-9213A5C12A95%40ix.netcom.com. For more options, visit https://groups.google.com/d/optout.
