Re: Can you temporarily turn off STDERR?

can’t change

http://codeforpeople.com/lib/ruby/session/session-2.4.0/README
http://codeforpeople.com/lib/ruby/open4/open4-0.5.1/README

in particular the Open4::spawn command. both are available as

This comes up often enough that I wonder if allowing IO#reopen to take a
block would be a good idea:

$stderr.reopen(’/dev/null’) do

Code here redirects to /dev/null

end

Code outside the block behaves normally

I thought this idea had been brought up before, and that there was some
downside to this, but I can’t find any references to it now.

Thoughts?

  • Dan

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On 8/25/06, Berger, Daniel [email protected] wrote:

I thought this idea had been brought up before, and that there was some
downside to this, but I can’t find any references to it now.

Thoughts?

  • Dan

How about this?

#!/usr/bin/env ruby

reopen_with_block.rb

class IO

alias_method :_orig_reopen, :reopen

def reopen(*args)
if block_given?
is_path = args.length == 2
path_or_io, mode_str = args
old_io = clone
path_or_io = File.open(path_or_io, mode_str || “w”) if is_path
_orig_reopen(path_or_io)
begin
yield
ensure
_orig_reopen(old_io)
path_or_io.close if is_path
end
else
_orig_reopen(*args)
end
end

end

if $0 == FILE
$stderr.reopen(‘error_log’, ‘w’) do
$stderr.puts “Stuff on error”
puts “normal stuff”
end

File.open(‘error_log_2’, “w”) do |file|
$stderr.reopen(file) do
$stderr.puts “Stuff on error 2”
puts “normal stuff 2”
end
end

$stderr.reopen(’/dev/null’) do
$stderr.puts “Stuff on error 3”
puts “normal stuff 3”
end

Make sure old way works

old_stderr = $stderr.clone
File.open(‘error_log_4’, ‘w’) do |log_file|
$stderr.reopen(log_file)
begin
$stderr.puts “Stuff on error 4”
puts “normal stuff 4”
ensure
$stderr.reopen(old_stderr)
end
end

begin
$stderr.reopen(‘error_log_5’, ‘w’) do
$stderr.puts “Stuff on error 5”
puts “normal stuff 5”
raise “This message courtesy of raise”
end
rescue => e
puts e
end

end

downside to this, but I can’t find any references to it now.

Thoughts?

Can’t handle threading sanely, for one.