+NAME
+
+ systemu
+
+SYNOPSIS
+
+ universal capture of stdout and stderr and handling of child process pid for
+ windows, *nix, etc.
+
+URIS
+
+ http://github.com/ahoward/systemu
+ http://rubyforge.org/projects/codeforpeople/
+
+INSTALL
+
+ gem install systemu
+
+HISTORY
+ 2.0.0
+ - versioning issue. new gem release.
+
+ 1.3.1
+ - updates for ruby 1.9.1
+
+ 1.3.0
+ - move to github
+
+ 1.2.0
+
+ - fixed handling of background thread management - needed
+ Thread.current.abort_on_exception = true
+
+ - fixed reporting of child pid, it was reported as the parent's pid before
+
+SAMPLES
+
+
+ <========< samples/a.rb >========>
+
+ ~ > cat samples/a.rb
+
+ #
+ # systemu can be used on any platform to return status, stdout, and stderr of
+ # any command. unlike other methods like open3/popen4 there is zero danger of
+ # full pipes or threading issues hanging your process or subprocess.
+ #
+ require 'systemu'
+
+ date = %q( ruby -e" t = Time.now; STDOUT.puts t; STDERR.puts t " )
+
+ status, stdout, stderr = systemu date
+ p [ status, stdout, stderr ]
+
+ ~ > ruby samples/a.rb
+
+ [#<Process::Status: pid 50931 exit 0>, "2011-12-11 22:07:30 -0700\n", "2011-12-11 22:07:30 -0700\n"]
+
+
+ <========< samples/b.rb >========>
+
+ ~ > cat samples/b.rb
+
+ #
+ # quite a few keys can be passed to the command to alter it's behaviour. if
+ # either stdout or stderr is supplied those objects should respond_to? '<<'
+ # and only status will be returned
+ #
+ require 'systemu'
+
+ date = %q( ruby -e" t = Time.now; STDOUT.puts t; STDERR.puts t " )
+
+ stdout, stderr = '', ''
+ status = systemu date, 'stdout' => stdout, 'stderr' => stderr
+ p [ status, stdout, stderr ]
+
+ ~ > ruby samples/b.rb
+
+ [#<Process::Status: pid 50936 exit 0>, "2011-12-11 22:07:30 -0700\n", "2011-12-11 22:07:30 -0700\n"]
+
+
+ <========< samples/c.rb >========>
+
+ ~ > cat samples/c.rb
+
+ #
+ # of course stdin can be supplied too. synonyms for 'stdin' include '0' and
+ # 0. the other stdio streams have similar shortcuts
+ #
+ require 'systemu'
+
+ cat = %q( ruby -e" ARGF.each{|line| puts line} " )
+
+ status = systemu cat, 0=>'the stdin for cat', 1=>stdout=''
+ puts stdout
+
+ ~ > ruby samples/c.rb
+
+ the stdin for cat
+
+
+ <========< samples/d.rb >========>
+
+ ~ > cat samples/d.rb
+
+ #
+ # the cwd can be supplied
+ #
+ require 'systemu'
+ require 'tmpdir'
+
+ pwd = %q( ruby -e" STDERR.puts Dir.pwd " )
+
+ status = systemu pwd, 2=>(stderr=''), :cwd=>Dir.tmpdir
+ puts stderr
+
+
+ ~ > ruby samples/d.rb
+
+ /private/var/folders/sp/nwtflj890qnb6z4b53dqxvlw0000gp/T
+
+
+ <========< samples/e.rb >========>
+
+ ~ > cat samples/e.rb
+
+ #
+ # any environment vars specified are merged into the child's environment
+ #
+ require 'systemu'
+
+ env = %q( ruby -r yaml -e" puts ENV[ 'answer' ] " )
+
+ status = systemu env, 1=>stdout='', 'env'=>{ 'answer' => 0b101010 }
+ puts stdout
+
+ ~ > ruby samples/e.rb
+
+ 42
+
+
+ <========< samples/f.rb >========>
+
+ ~ > cat samples/f.rb
+
+ #
+ # if a block is specified then it is passed the child pid and run in a
+ # background thread. note that this thread will __not__ be blocked during the
+ # execution of the command so it may do useful work such as killing the child
+ # if execution time passes a certain threshold
+ #
+ require 'systemu'
+
+ looper = %q( ruby -e" loop{ STDERR.puts Time.now.to_i; sleep 1 } " )
+
+ status, stdout, stderr =
+ systemu looper do |cid|
+ sleep 3
+ Process.kill 9, cid
+ end
+
+ p status
+ p stderr
+
+ ~ > ruby samples/f.rb
+
+ #<Process::Status: pid 50956 SIGKILL (signal 9)>
+ "1323666451\n1323666452\n1323666453\n"
+
+