在Go中获取给定文件描述符的文件大小

Question

If given a path, I would use this to get file size

file, _ := os.Open(path)
fi, _ := file.Stat()
fsuze := fi.Size()

But if only given fd, how can I get the file size? Is there any way in Go like this in C:

lseek(fd, 0, SEEK_END)

Answer 1

You create a new *os.File from a file descriptor using the os.NewFile function.

You can do it exactly the same way as in C, using Seek

offset, err := f.Seek(0, os.SEEK_END)

But since you have the *os.File already, you can call Stat even if it was derived directly from the file descriptor.