METRIC / SAE Indicator for pyVCP

#<_metric> - Return 1 if G21 is on, else 0.
#<_imperial> - Return 1 if G20 is on, else 0.

emcStatus->task.programUnits
emcStatus->motion.traj.linearUnits

    {(char*)"linear_units", T_DOUBLE, O(motion.traj.linearUnits), READONLY},

typedef int CANON_UNITS;
#define CANON_UNITS_INCHES 1
#define CANON_UNITS_MM 2
#define CANON_UNITS_CM 3

#!/usr/bin/env python
import linuxcnc
import hal,time

metric = False

h = hal.component("metric_status")
h.newpin("out", hal.HAL_FLOAT, hal.HAL_OUT)
h.ready()

status = linuxcnc.stat()
try:
    while 1:
        # update once a second
        time.sleep(1)
        # poll current status
        status.poll()
        # search active G codes
        # only check whole numbered Gcodes
        for i in sorted(status.gcodes[1:]):
            if i == -1: continue
            if i % 10 == 0:
                if i == 210:
                    metric = True
                    break
                elif i == 200:
                    metric = False
                    break
        # Update pin
        h['out'] = metric
except KeyboardInterrupt:
    raise SystemExit

#!/usr/bin/env python
import linuxcnc
import hal,time

metric = False

h = hal.component("unit_status")
h.newpin("out", hal.HAL_BIT, hal.HAL_OUT)
h.ready()

status = linuxcnc.stat()
try:
    while 1:
        # update once a second
        time.sleep(1)
        # poll current status
        status.poll()
        # check program units
        if status.program_units == 2:
                metric = True
        if status.program_units == 1:
                metric = False
        # Update pin
        h['out'] = metric
except KeyboardInterrupt:
    raise SystemExit