module Open3 extend self def popen3(*cmd) pw = IO::pipe # pipe[0] for read, pipe[1] for write pr = IO::pipe pe = IO::pipe pid = fork{ # child fork{ # grandchild pw[1].close STDIN.reopen(pw[0]) pw[0].close pr[0].close STDOUT.reopen(pr[1]) pr[1].close pe[0].close STDERR.reopen(pe[1]) pe[1].close exec(*cmd) } exit!(0) } pw[0].close pr[1].close pe[1].close Process.waitpid(pid) pi = [pw[1], pr[0], pe[0]] pw[1].sync = true if defined? yield begin return yield(*pi) ensure Process.detach(pid) if pid pi.each { |p| p.close unless p.closed? } end end pi end end