Difference between USER_M_PATH and nc_files path

USER_M_PATH = myfuncs:/tmp/mcodes:experimentalmcodes - Specifies a list of colon (:) separated directories for user defined functions. Directories are specified relative to the current directory for the ini file or as absolute paths. The list must contain no intervening whitespace.

A search is made for each possible user defined function, typically (M100-M199). The search order is:

    [DISPLAY]PROGRAM_PREFIX (if specified)

    If [DISPLAY]PROGRAM_PREFIX is not specified, search the default location: nc_files

    Then search each directory in the list [RS274NGC]USER_M_PATH

    The first executable M1xx found in the search is used for each M1xx.

~/linuxcnc/nc_files

~/linuxcnc/configs/my_config/nc_files

[DISPLAY]
PROGRAM_PREFIX = ./d1
...
[RS274NGC]
USER_M_PATH= ./d2:./d3:./nc_files
...

[DISPLAY]
#PROGRAM_PREFIX=./d1
...
[RS274NGC]
USER_M_PATH= ./d2:./d3:./nc_files
...

$ cat d1/M111
#!/bin/bash
halcmd setp motion.analog-in-00 1.111  # 1.xxx for dir d1
$ cat d2/M111
#!/bin/bash
halcmd setp motion.analog-in-00 2.111  # 2.xxx for dir d2
# ... etc.
$ cat nc_files/M111
#!/bin/bash
halcmd setp motion.analog-in-00 0.111  # 0.xxx for dir nc_files
[code]

Note that there are several files with the same name to
illustrate how the search works:
[code]
├── d1
│   └── M111
├── d2
│   ├── M111
│   └── M112
├── d3
│   ├── M111
│   ├── M112
│   └── M113
├── nc_files
    └── M111

  mkdir /tmp/demo       # make a test directory
  cd    /tmp/demo       # work in that directory
  wget https://forum.linuxcnc.org/media/kunena/attachments/512/mpath_demo.zip
  unzip mpath_demo.zip  # extract archive
  linuxcnc demo1.ini &  # try demo1
  # F1 (clear Estop)
  # F2 (machine On)
  # R  (run included program named demo.ngc)
  # menu/Exit

  linuxcnc demo2.ini & # repeat for demo2