Module: Rubysh::Util

Defined in:
lib/rubysh/util.rb

Class Method Summary collapse

Class Method Details

.dup2(fildes, fildes2) ⇒ Object

Should really just shell out to dup2, but looks like we’d need a C extension to do so. The concurrency story here is a bit off, and this probably doesn’t copy over all FD state properly. Should be fine for now.



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# File 'lib/rubysh/util.rb', line 32

def self.dup2(fildes, fildes2)
  original = io_without_autoclose(fildes)

  begin
    copy = io_without_autoclose(fildes2)
  rescue Errno::EBADF
  else
    copy.close
  end

  # For some reason, Ruby 1.9 doesn't seem to let you close
  # stdout/sterr. So if we didn't manage to close it above, then
  # just use reopen. We could get rid of the close attempt above,
  # but I'd rather leave this code as close to doing the same
  # thing everywhere as possible.
  begin
    copy = io_without_autoclose(fildes2)
  rescue Errno::EBADF
    res = original.fcntl(Fcntl::F_DUPFD, fildes2)
    Rubysh.assert(res == fildes2, "Tried to open #{fildes2} but ended up with #{res} instead", true)
  else
    copy.reopen(original)
  end
end

.io_without_autoclose(fd_num) ⇒ Object

Leaks memory in 1.8 (needed to avoid Ruby 1.8’s IO autoclose behavior), and so you should only use it in pre-1.9 right before execing.



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# File 'lib/rubysh/util.rb', line 16

def self.io_without_autoclose(fd_num)
  fd_num = to_fileno(fd_num)
  io = IO.new(fd_num)

  if io.respond_to?(:autoclose)
    io.autoclose = false
  else
    hold(io)
  end
  io
end

.set_cloexec(file, enable = true) ⇒ Object 



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# File 'lib/rubysh/util.rb', line 57

def self.set_cloexec(file, enable=true)
  file = io_without_autoclose(file) unless file.kind_of?(IO)
  value = enable ? Fcntl::FD_CLOEXEC : 0
  file.fcntl(Fcntl::F_SETFD, value)
end

.to_fileno(file) ⇒ Object 



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# File 'lib/rubysh/util.rb', line 5

def self.to_fileno(file)
  if file.respond_to?(:fileno)
    file.fileno
  else
    file
  end
end