如何在Go中获取文件长度？

I looked up golang.org/pkg/os/#File , but still have no idea. Seems there is no way to get file length, did I miss something?

How to get file length in Go?

(*os.File).Stat() returns a os.FileInfo value, which in turn has a Size() method. So, given a file f, the code would be akin to

fi, err := f.Stat()
if err != nil {
  // Could not obtain stat, handle error
}

fmt.Printf("The file is %d bytes long", fi.Size())

Slightly more verbose answer:

file, err := os.Open( filepath ) 
if err != nil {
    log.Fatal(err)
}
fi, err := file.Stat()
if err != nil {
    log.Fatal(err)
}
fmt.Println( fi.Size() )

If you don't want to open the file, you can directly call os.Stat instead.

fi, err := os.Stat("/path/to/file");
if err != nil {
    return err
}
// get the size
size := fi.Size()