Re: Problems with current file descriptor

[winter <winter.sui@gmail.com>]

2005/10/27, Sergio Paracuellos <sparacuellos@lock-linux.com>:
> > current file ?what is meaning?
> > for exmaple ,you opened 3 file, file1,file2, file3. which is current file?
>
> Sorry, I want the last file I used. For example if I just have done "cat
> foobar" the file I want is this.
>
if you used the command "cat foobar", the linux kernel's do the
following 3 phase for you:
  1. open() --> sys_open()  // in this phase, the filp struct is
create and save at
                                        // current->files->fd[x]. the x=fd.
  2. read() --> sys_read()    // in this phase, read file's data, the
fd is not changed.
  3. close() --> sys_close() // in this phase, free the filp struct.
the result is
                                       // current->files->fd[fd] = 0.
so it is, kernel can not save the last file which you opend.
which  phase you want get the path at?