module Shell_uq:Run shell commands within Unixqueuessig..end
Shell_sys for
 more information.Shell_sys.configure_job_handlers and
 Shell_sys.install_job_handlers for this purpose. This is not
 done automatically.
 Note that this has a global side effect on the whole process, because
 there is only one set of signal handlers.
class type['a]job_handler_engine_type =object..end
job and the job_instance.
class call_engine :?ignore_error_code:bool -> ?mode:Shell_sys.group_mode -> ?stdin:Shell.producer -> ?stdout:Shell.consumer -> ?stderr:Shell.consumer -> Shell_sys.command list -> Unixqueue.event_system ->[Shell_sys.job_status]job_handler_engine_type
Shell.call.
 All examples presented for the Shell module can be easily rewritten
 for Shell_uq. For example, to call "ls" and collect the result in a
 buffer, use this piece of code:
 let ues = Unixqueue.create_unix_event_system();;
 let b = Buffer.create 10;;
 let e = new call_engine ~stdout:(Shell.to_buffer b) [ Shell.command "ls" ];;
 Unixqueue.run ues;;
 let r = Buffer.contents b;;
 
 This means, one simply creates a call_engine instead of invoking
 Shell.call, and then runs the queue. Note that you must look at
 e#state to find out whether the engine e produced an error, no
 exception is raised in this case.
 It is allowed (and somehow the purpose of this module) to create
 several job engines, and let them run in parallel.
