From: nobu.nokada@...
Date: 2002-01-31T01:01:11+09:00
Subject: Re: trouble changing mtime on symlinks

Hi,

At Thu, 31 Jan 2002 00:03:59 +0900,
Simon Strandgaard <0bz63fz3m1qt3001@sneakemail.com> wrote:
> I want to sync the timestamp of the symlink with the original file, they
> has to be exact.  There is unfortunatly no File.lutime is there some other
> way around it in ruby?

If your system has lutime(2), you can use Kernel#syscall.

  class File
    SYS_lutime = # see /usr/include/sys/syscall.h or somewhere.
    def lutime(atime, mtime, *files)
      t = [atime.to_i, mtime.to_i].pack("ll")
      files.each do |f|
        syscall(SYS_lutime, f, t)
      end.size
    end
  end

You may get SYS_lutime value with this.

$ {echo '#include <sys/syscall.h>';echo SYS_utime;}|gcc -E -|tail -1

-- 
Nobu Nakada