diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md index 0781abb6ed..61d85543d1 100644 --- a/activesupport/CHANGELOG.md +++ b/activesupport/CHANGELOG.md @@ -1,4 +1,5 @@ ## Rails 4.0.0 (unreleased) ## +* Kernel#capture can catch output from subprocesses *Dmitry Vorotilin* * `to_xml` conversions now use builder's `tag!` method instead of explicit invocation of `method_missing`. diff --git a/activesupport/lib/active_support/core_ext/kernel/reporting.rb b/activesupport/lib/active_support/core_ext/kernel/reporting.rb index bc97da6ef2..7b518821c8 100644 --- a/activesupport/lib/active_support/core_ext/kernel/reporting.rb +++ b/activesupport/lib/active_support/core_ext/kernel/reporting.rb @@ -1,4 +1,5 @@ require 'rbconfig' +require 'tempfile' module Kernel # Sets $VERBOSE to nil for the duration of the block and back to its original @@ -66,19 +67,33 @@ module Kernel # Captures the given stream and returns it: # - # stream = capture(:stdout) { puts 'Cool' } - # stream # => "Cool\n" + # stream = capture(:stdout) { puts 'notice' } + # stream # => "notice\n" + # + # stream = capture(:stderr) { warn 'error' } + # stream # => "error\n" + # + # even for subprocesses: + # + # stream = capture(:stdout) { system('echo notice') } + # stream # => "notice\n" + # + # stream = capture(:stderr) { system('echo error 1>&2') } + # stream # => "error\n" def capture(stream) - begin - stream = stream.to_s - eval "$#{stream} = StringIO.new" - yield - result = eval("$#{stream}").string - ensure - eval("$#{stream} = #{stream.upcase}") - end + stream = stream.to_s + captured_stream = Tempfile.new(stream) + stream_io = eval("$#{stream}") + origin_stream = stream_io.dup + stream_io.reopen(captured_stream) - result + yield + + stream_io.rewind + return captured_stream.read + ensure + captured_stream.unlink + stream_io.reopen(origin_stream) end alias :silence :capture diff --git a/activesupport/test/core_ext/kernel_test.rb b/activesupport/test/core_ext/kernel_test.rb index 439bc87323..1583c1fa32 100644 --- a/activesupport/test/core_ext/kernel_test.rb +++ b/activesupport/test/core_ext/kernel_test.rb @@ -51,6 +51,8 @@ class KernelTest < ActiveSupport::TestCase def test_capture assert_equal 'STDERR', capture(:stderr) { $stderr.print 'STDERR' } assert_equal 'STDOUT', capture(:stdout) { print 'STDOUT' } + assert_equal "STDERR\n", capture(:stderr) { system('echo STDERR 1>&2') } + assert_equal "STDOUT\n", capture(:stdout) { system('echo STDOUT') } end end