On Sun, Jun 25, 2017 at 2:19 PM, Farid Shahy <fsh...@gmail.com> wrote:
>
> I have opened two files and want to use io.Copy to read from one file and
> write to another, but it does not work.
> If I close first file and then reopen it io.Copy will work correctly.Can
> anybody please help on this issue?
>
>> f1, err := os.Create("File1.txt")
>> checkErr(err, "Error creating File1.txt")
>> // defer f1.Close()
>>
>> f2, err := os.Create("File2.txt")
>> checkErr(err, "Error creating File2.txt")
>> defer f2.Close()
>>
>> c1, err := f1.WriteString("Hello Pipe!")
>> checkErr(err, "Error writting to File1.txt")
>> fmt.Println("Written Count - f1: ", c1)
>>
>> err = f1.Sync()
>> checkErr(err, "Error writting File1.txt to disk.")
>>
>> // f1.Close()
>> // f1, err = os.OpenFile("File1.txt", os.O_RDWR, 0664)
>> // defer f1.Close()
>> // checkErr(err, "Error opening File1.txt again.")
>>
>> c2, err := io.Copy(f2, f1)
>> checkErr(err, "Error copying File1txt to File2.txt.")
>> fmt.Println("Written Count - f2: ", c2)You need to reset the file position of f1 back to the start, using the Seek method. (By the way, you don't need to call Sync.) Ian -- 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. For more options, visit https://groups.google.com/d/optout.
