That’s a good case of dynamic type checking and good documentation > On May 21, 2019, at 5:20 PM, roger peppe <rogpe...@gmail.com> wrote: > > Probably it's not a Closer because that would imply that Close would close > its underlying writer too, but then it would need to take a WriteCloser which > would make it less general. > >> On Tue, 21 May 2019, 19:02 Robert Engels, <reng...@ix.netcom.com> wrote: >> 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. > > -- > 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/CAJhgacidQJLbjQ16BBDLOQ57q5BAbqJvu1Y57-itoAV9DtPDLQ%40mail.gmail.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/F2380E32-37C9-4056-9E06-DC674F8832EF%40ix.netcom.com. For more options, visit https://groups.google.com/d/optout.
