ecFlow's documentation is now on readthedocs!

In this exercise, we will use one of the command-line features of ecflow.

We will use query command, to determine the state of a node, event, meter.  An alternative to the query command would be to use the python API.

The general format is:

query command
ecflow_client --query arg1 arg2 arg3


  • 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

Here are some examples using the query command:

  • state=$(ecflow_client --query state /path/to/node)                                                          # return node state 
  • dstate=$(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 
  • value=$(ecflow_client --query variable /path/to/task/with/var:var_name )                    # returns the variable value  
  • limit_value=$(ecflow_client --query limit  /path/to/task/with/limit:limit_name)              # returns the current value of the limit 

  • limit_max=$(ecflow_client --query limit_max /path/to/task/with/limit:limit_name)        # returns the max value of the limit 

  • label_value=$(ecflow_client --query label %ECF_NAME%:label_name)                          # returns the current value of the label 
  • value=$(ecflow_client --query trigger /path/to/node/with/trigger \"/suite/task == complete\")   # return true if expression evaluates false otherwise

Ecf Script

We will create new query task

 %include <head.h>

meter=$(ecflow_client --query meter /test/f1/t1:progress)
while [[ $meter -lt 100 ]]
    sleep 2
    meter=$(ecflow_client --query meter /test/f1/t1:progress)
    eventa=$(ecflow_client --query event /test/f1/t2:a)
    eventb=$(ecflow_client --query event /test/f1/t2:b)
    t5_state=$(ecflow_client --query state /test/f1/t5)
    ecflow_client --label=query "meter($meter) eventa($eventa) eventb($eventb) t5_state($t5_state)"

%include <tail.h>


# Definition of the suite test.
suite test
 edit ECF_INCLUDE "$HOME/course"    # replace '$HOME' with the path to your home directory
 edit ECF_HOME    "$HOME/course"
 family f1
     edit SLEEP 20
     task t1
         meter progress 1 100 90
     task t2
         trigger t1 eq complete
         event a
         event b
     task t3
         trigger t2:a
     task t4
         trigger t2 eq complete
         complete t2:b
     task t5
         trigger t1:progress ge 30
     task t6
         trigger t1:progress ge 60
     task t7
         trigger t1:progress ge 90
     task query
         label query ""


import os
from ecflow import Defs,Suite,Family,Task,Edit,Trigger,Complete,Event,Meter

def create_family_f1():
    return Family("f1",
                Task("t1", Meter("progress", 1, 100, 90)),
                Task("t2", Trigger("t1 == complete"), Event("a"), Event("b")),
                Task("t3", Trigger("t2:a")),
                Task("t4", Trigger("t2 == complete"), Complete("t2:b")),
                Task("t5", Trigger("t1:progress ge 30")),
                Task("t6", Trigger("t1:progress ge 60")),
                Task("t7", Trigger("t1:progress ge 90")),
print("Creating suite definition")  
home = os.path.join(os.getenv("HOME"), "course")
defs = Defs( 

print("Checking job creation: .ecf -> .job0")  

print("Saving definition to file 'test.def'")

What to do

  1. Go back to the previous exercise where we finished adding a meter.
  2. Edit the definition file or python to add the modifications. You should only need to add a task query.
  3. create file query.ecf to call ecflow_client –query
  4. Replace the suite
    python: python3 ; python3
    text:      ecflow_client --suspend=/test   ; ecflow_client --replace=/test  test.def
  5. Observe the tasks in ecflow_ui
  6. Modify query.ecf, to use ecflow_client --query variable, and show this variable in the query label. 

    Although a variable is accessible in the script by using %VAR%, ecflow_client --query variable might be more useful in an interactive shell or a different server