[ANN] open4-0.2.0

ruby-talk
1

URIS

   http://rubyforge.org/frs/?group_id=1024
   http://www.codeforpeople.com/lib/ruby/

SYNOPSIS

   open child process with handles on pid, stdin, stdout, and stderr

HISTORY

   0.2.0 :
     - added exception marshaled from child -> parent when exec fails. thanks
       to jordan breeding for a patch (yay!) and paul brannan for this most
       excellent idea.

   0.1.0 :
     - fixed docs to correctly show return value of popen4 (pid first not last).
       thanks Stefanie Tellex <stefie10@alum.mit.edu> for catching this.
   0.0.0 :
     - initial version

INSTALL

   ~> gem install open4

SAMPLES

   simple usage:

     jib:~/eg/ruby/open4/open4-0.2.0 > cat sample/simple.rb
     require "open4"

     pid, stdin, stdout, stderr = Open4::popen4 "sh"

     stdin.puts "echo 42.out"
     stdin.puts "echo 42.err 1>&2"
     stdin.close

     ignored, status = Process::waitpid2 pid

     puts "pid : #{ pid }"
     puts "stdout : #{ stdout.read.strip }"
     puts "stderr : #{ stderr.read.strip }"
     puts "status : #{ status.inspect }"
     puts "exitstatus : #{ status.exitstatus }"

     jib:~/eg/ruby/open4/open4-0.2.0 > ruby sample/simple.rb
     pid : 17273
     stdout : 42.out
     stderr : 42.err
     status : #<Process::Status: pid=17273,exited(0)>
     exitstatus : 0

   block form - child process is automatically waited for:

     jib:~/eg/ruby/open4/open4-0.2.0 > cat sample/block.rb
     require 'open4'

     status =
       Open4::popen4("sh") do |pid, stdin, stdout, stderr|
         stdin.puts "echo 42.out"
         stdin.puts "echo 42.err 1>&2"
         stdin.close

         puts "pid : #{ pid }"
         puts "stdout : #{ stdout.read.strip }"
         puts "stderr : #{ stderr.read.strip }"
       end

         puts "status : #{ status.inspect }"
         puts "exitstatus : #{ status.exitstatus }"

     jib:~/eg/ruby/open4/open4-0.2.0 > ruby sample/block.rb
     pid : 17295
     stdout : 42.out
     stderr : 42.err
     status : #<Process::Status: pid=17295,exited(0)>
     exitstatus : 0

   exceptions are marshaled from child to parent if fork/exec fails:

     jib:~/eg/ruby/open4/open4-0.2.0 > cat sample/exception.rb
     require "open4"
     Open4::popen4 "noexist"

     jib:~/eg/ruby/open4/open4-0.2.0 > ruby sample/exception.rb
     /dmsp/reference/ruby-1.8.1//lib/ruby/site_ruby/open4.rb:100:in `popen4': No such file or directory - noexist (Errno::ENOENT)
             from sample/exception.rb:3

AUTHOR

   ara.t.howard@noaa.gov

LICENSE

   ruby's

enjoy.

-a

···

--
judge your success by what you had to give up in order to get it.
- h.h. the 14th dali lama