
.. _query_cli:

query
*****



.. rubric:: Description




Currently, the ecflow python API provides quite extensive functionality.

However sometimes we just want to query simple state on the command
line, and using the full-blown python API, can seem like overkill.

Query can be used in these simple cases

Query the status of attributes i.e. state, dstate, repeat,event, meter,
variable, limit , limit_max or trigger expression without blocking

-  state return   [unknown \| complete \| queued  \|  aborted \|
   submitted \| active] to standard out

-  dstate return [unknown \| complete \| queued  \|  aborted \|
   submitted \| active \| suspended] to standard out

-  |  repeat   returns current value as a string to standard out, can
     also retrieve the next and previous value of the repeat. See
     examples below
   | The next/prev will always stay within repeat bounds. hence calling
     'next' on the last value of the repeat, will return last value.
   | Likewise calling 'prev' on a repeat that has not started, will
     return the first/start value.

-  event           return 'set' \| 'clear' to standard out

-  meter          return value of the meter to standard out

-  limit              return the current value of the limit

-  limit_max  return the maximum value of the limit

-  label             return new value otherwise the old value

-  variable      return value of the variable, repeat or generated
   variable to standard out, will search up the node tree

-  trigger        returns 'true' if the expression is true, otherwise
   'false'

If this command is called within a '.ecf' script we will additionally log the task calling this command

This is required to aid debugging for excessive use of this command

The command will fail if the node path to the attribute does not exist
in the definition and if:

-  repeat                The repeat is not found

-  event                  The event is not found

-  meter                 The meter is not found

-  limit/limit_max   The limit is not found

-  label                   The label is not found

-  variable No user or generated variable or repeat of that name found
   on node, or any of its parents

-  trigger  Trigger does not parse, or reference to nodes/attributes in
   the expression are not valid

Arguments:

-  arg1 = [ state \| event \| meter \| label \| variable \| trigger \|
   limit \| limit_max ]

-  arg2 = <path> \| <path>:name where name is name of a event,
   meter,limit or variable

-  arg3 = trigger expression (optional)  \| prev \| next    # prev,next
   only used when arg1 is repeat

Usage:

.. code-block:: shell
  
   state=$(ecflow_client --query state /path/to/node)                                              # return node state to standard out
   dstate=$(ecflow_client --query dstate /path/to/node)                                            # state that can includes suspended
   value=$(ecflow_client --query repeat /path/to/node )                                            # return the current value as a string
   value=$(ecflow_client --query repeat /path/to/node   prev  )                                    # return the previous value as a string, does not modify real repeat
   value=$(ecflow_client --query repeat /path/to/node   next)                                      # return the next value as a string, does not modify real repeat
   event=$(ecflow_client --query event /path/to/task/with/event:event_name)                        # return set | clear to standard out
   meter=$(ecflow_client --query meter /path/to/task/with/meter:meter_name)                        # returns the current value of the meter to standard out
   value=$(ecflow_client --query variable /path/to/task/with/var:var_name )                        # returns the variable value to standard out
   limit_value=$(ecflow_client --query limit  /path/to/task/with/limit:limit_name)                 # returns the current value of the limit to standard out
   limit_max=$(ecflow_client --query limit_max /path/to/task/with/limit:limit_name)                # returns the max value of the limit to standard out
   label_value=$(ecflow_client --query label %ECF_NAME%:label_name)                                # returns the current value of the label to standard out
   value=$(ecflow_client --query trigger /path/to/node/with/trigger \"/suite/task == complete\")   # return true if expression evaluates false otherwise



.. rubric:: Output of :code:`--help=query`



The following help text is generated by :code:`ecflow_client --help=query`

::

   
   query
   -----
   
   Query the status of attributes
    i.e state,dstate,repeat,event,meter,label,variable or trigger expression without blocking
    - state     return [unknown | complete | queued |             aborted | submitted | active] to standard out
    - dstate    return [unknown | complete | queued | suspended | aborted | submitted | active] to standard out
    - repeat    returns current value as a string to standard out
    - event     return 'set' | 'clear' to standard out
    - meter     return value of the meter to standard out
    - limit     return current value of limit to standard out
    - limit_max return limit max value to standard out
    - label     return new value otherwise the old value
    - variable  return value of the variable, repeat or generated variable to standard out,
                will search up the node tree
    - trigger   returns 'true' if the expression is true, otherwise 'false'
   
   If this command is called within a '.ecf' script we will additionally log the task calling this command
   This is required to aid debugging for excessive use of this command
   The command will fail if the node path to the attribute does not exist in the definition and if:
    - repeat   The repeat is not found
    - event    The event is not found
    - meter    The meter is not found
    - limit/limit_max The limit is not found
    - label    The label is not found
    - variable No user or generated variable or repeat of that name found on node, or any of its parents
    - trigger  Trigger does not parse, or reference to nodes/attributes in the expression are not valid
   Arguments:
     arg1 = [ state | dstate | repeat | event | meter | label | variable | trigger | limit | limit_max ]
     arg2 = <path> | <path>:name where name is name of a event, meter, label, limit or variable
     arg3 = trigger expression | prev | next # prev,next only used when arg1 is repeat
   
   Usage:
    ecflow_client --query state /                                     # return top level state to standard out
    ecflow_client --query state /path/to/node                         # return node state to standard out
    ecflow_client --query dstate /path/to/node                        # state that can included suspended
    ecflow_client --query repeat /path/to/node                        # return the current value as a string
    ecflow_client --query repeat /path/to/node prev                   # return the previous value as a string
    ecflow_client --query repeat /path/to/node next                   # return the next value as a string
    ecflow_client --query event /path/to/task/with/event:event_name   # return set | clear to standard out
    ecflow_client --query meter /path/to/task/with/meter:meter_name   # returns the current value of the meter to standard out
    ecflow_client --query limit /path/to/task/with/limit:limit_name   # returns the current value of the limit to standard out
    ecflow_client --query limit_max /path/to/task/with/limit:limit_name # returns the max value of the limit to standard out
    ecflow_client --query label /path/to/task/with/label:label_name   # returns the current value of the label to standard out
    ecflow_client --query variable /path/to/task/with/var:var_name    # returns the variable value to standard out
    ecflow_client --query trigger /path/to/node/with/trigger "/suite/task == complete" # return true if expression evaluates false otherwise
   
   
   The client considers, for both user and child commands, the following environment variables:
   
     ECF_HOST <string> [mandatory*]
       The main server hostname; default value is 'localhost'
     ECF_PORT <int> [mandatory*]
       The main server port; default value is '3141'
     ECF_SSL <any> [optional*]
       Enable secure communication between client and server.
     ECF_HOSTFILE <string> [optional]
       File that lists alternate hosts to try, if connection to main host fails
     ECF_HOSTFILE_POLICY <string> [optional]
       The policy ('task' or 'all') to define which commands consider using alternate hosts.
   
   The options marked with (*) must be specified in order for the client to communicate
   with the server, either by setting the environment variables or by specifying the
   command line options.
   

