TeeRb - Several ways to capture and tee Ruby's standard input and output

• Pipe calls to $stdout and $stderr to a file
• Pipe calls to $stdout and $stderr to an instance of Ruby's logger class
• Pipe calls to an instance of Ruby's logger class to $stdout

Usage

# Tee $stdout and $stderr to several files
log_file = File.open("debug.log", "a")
tee = TeeRb::Tee.new(log_file)
tee.enable

puts 'puts hello'
$stdout.puts 'stdout hello'
$stderr.puts 'stderr hello'

tee.disable

puts 'puts hello'
$stdout.puts 'stdout hello'
$stderr.puts 'stderr hello'

# same as above but with block syntax
log_file = File.open("debug.log", "a")
TeeRb::Tee.new(log_file) do
  puts 'puts hello'
  $stdout.puts 'stdout hello'
  $stderr.puts 'stderr hello'
end


# Capture $stdout and $stderr and send it through `logger`
require 'logger'
log_file = File.open("debug.log", "a")
logger = Logger.new(log_file)
tee = TeeRb::LoggerTee.new(logger)
tee.enable

logger.warn "hello"
$stderr.puts "stderr hello"
puts "stdout hello"


# Pipe calls to an instance of Ruby's logger class to $stdout
require 'logger'
log_file = File.open("debug.log", "a")
logger = Logger.new(TeeRb::IODelegate.new(log_file, STDOUT))
logger.warn "warn"
$stderr.puts "stderr hello"
puts "stdout hello"

Problems

This only works for $stdout and $stderr and not for STDOUT and STDERR, since they constants that should not be reassigned.