Open3 grants you access to stdin, stdout, stderr and a thread to wait the child process when running another program. You can specify various attributes, redirections, current directory, etc., of the program as Process.spawn.

• ::popen3 : pipes for stdin, stdout, stderr

• ::popen2 : pipes for stdin, stdout

• ::popen2e : pipes for stdin, merged stdout and stderr

• ::capture3 : give a string for stdin. get strings for stdout, stderr

• ::capture2 : give a string for stdin. get a string for stdout

• ::capture2e : give a string for stdin. get a string for merged stdout and stderr

• ::pipeline_rw : pipes for first stdin and last stdout of a pipeline

• ::pipeline_r : pipe for last stdout of a pipeline

• ::pipeline_w : pipe for first stdin of a pipeline

• ::pipeline_start : run a pipeline and don't wait

• ::pipeline : run a pipeline and wait