univeral capture of stdout and stderr and handling of child process pid for windows, *nix, etc.
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
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
[#<:status: pid exit>, "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? '< stdout, 'stderr' => stderr p [ status, stdout, stderr ]
~ > ruby samples/b.rb
[#<:status: pid exit>, "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
#<:status: pid sigkill> "1323666451\n1323666452\n1323666453\n"