[westurner]

Remembered to add the `2>&1` stderr>stdout output redirection:

  ps wxa | grep <cmd>  # or pgrep
  strace -f -f -e trace=file <cmd> 2>&1 | grep -v '-1 ENOENT (No such file or directory)$'

Bash manual > 3. Basic Shell Features > 3.6 Redirections: https://www.gnu.org/software/bash/manual/html_node/Redirecti...

In lieu of strace, IDK how fast `ls -al /proc/${pid}/fd/*` can be polled and logged in search of which config file it is; almost like `lsof -n`:

  pid=$$ # this $SHELL's pid
  help set; # help help
  (set -B; cat /proc/"${pid}"/{cmdline,environ}) \
    | tr '\0' $'\n'

  (while 1; do echo \#$pid; ls -al /proc/${pid}/fd/*; done) | tee "file_handle_to_file_path.${pid}.log"
  # Ctrl-C

It's good Configuration Management practice to wrap managed config with a preamble/postamble indicating at least that some code somewhere wrote that and may overwrite whatever a user might manually change it to (prior to the configuration management system copying over or re-templating the config file content, thus overwriting any manual modifications)

  ## < managed by config_mgmt_system_xyz (in path.to.module.callable) >
  ## </ managed>

[hawski]

I prefer to use process substitution (not in POSIX):

  strace -f -e trace=file -o >(grep -v ENOENT) <cmd>