find(1) . -not -path "./node_modules/" -not -path "./dist/" | grep(1) -iP '\.mjs$' | xargs(1) -n1 -I{} -P32 $0 "{}" "${counter_dirname}";
search for files in a directory hierarchy
find [-H] [-L] [-P] [-D debugopts] [-Olevel] [path...] [expression]
-not expr
       Same as ! expr, but not POSIX compliant.
-path pattern
       File  name  matches  shell pattern pattern.  The metacharacters do not treat `/' or `.' specially;
       so, for example,
                 find . -path "./sr*sc"
       will print an entry for a directory called `./src/misc'  (if  one  exists).   To  ignore  a  whole
       directory  tree, use -prune rather than checking every file in the tree.  For example, to skip the
       directory `src/emacs' and all files and directories under it, and print the  names  of  the  other
       files found, do something like this:
                 find . -path ./src/emacs -prune -o -print
       Note  that  the  pattern match test applies to the whole file name, starting from one of the start
       points named on the command line.  It would only make sense to use an absolute path name  here  if
       the  relevant start point is also an absolute path.  This means that this command will never match
       anything:
                 find bar -path /foo/bar/myfile -print
       The predicate -path is also supported by HP-UX find and will be in a forthcoming  version  of  the
       POSIX standard.
Pipelines
    A  pipeline is a sequence of one or more commands separated by one of the control operators | or |&.  The
    format for a pipeline is:

           [time [-p]] [ ! ] command [ [||&] command2 ... ]

    The standard output of command is connected  via  a  pipe  to  the  standard  input  of  command2.   This
    connection  is performed before any redirections specified by the command (see REDIRECTION below).  If |&
    is used, the standard error of command is connected to command2's standard input through the pipe; it  is
    shorthand  for  2>&1  |.   This  implicit  redirection  of  the  standard  error  is  performed after any
    redirections specified by the command.

    The return status of a pipeline is the exit status of the last command, unless  the  pipefail  option  is
    enabled.   If  pipefail  is  enabled,  the  pipeline's return status is the value of the last (rightmost)
    command to exit with a non-zero status, or zero if all commands exit successfully.  If the reserved  word
    !   precedes  a  pipeline, the exit status of that pipeline is the logical negation of the exit status as
    described above.  The shell waits for all commands in the pipeline to terminate before returning a value.

    If the time reserved word precedes a pipeline, the elapsed as well as user and system  time  consumed  by
    its execution are reported when the pipeline terminates.  The -p option changes the output format to that
    specified by POSIX.  When the shell is in posix mode, it does not recognize time as a  reserved  word  if
    the  next  token begins with a `-'.  The TIMEFORMAT variable may be set to a format string that specifies
    how the timing information should be displayed; see the description of TIMEFORMAT under  Shell  Variables
    below.

    When the shell is in posix mode, time may be followed by a newline.  In this case, the shell displays the
    total user and system time consumed by the shell and its children.  The TIMEFORMAT variable may  be  used
    to specify the format of the time information.

    Each command in a pipeline is executed as a separate process (i.e., in a subshell).
print lines matching a pattern
-i, --ignore-case
       Ignore case distinctions in both the PATTERN and the input files.  (-i is specified by POSIX.)
-P, --perl-regexp
       Interpret PATTERN as a Perl regular expression (PCRE, see below).  This is highly experimental and
       grep -P may warn of unimplemented features.
grep searches the named input FILEs (or standard input if no files are named, or if a single hyphen-minus
(-) is given as file name) for lines containing a match to the given PATTERN.  By  default,  grep  prints
the matching lines.
build and execute command lines from standard input
--max-args=max-args
-n max-args
       Use at most max-args arguments per command line.  Fewer than max-args arguments will  be  used  if
       the  size (see the -s option) is exceeded, unless the -x option is given, in which case xargs will
       exit.
-I replace-str
       Replace occurrences of replace-str in the initial-arguments with names read from  standard  input.
       Also,  unquoted  blanks  do  not  terminate  input  items;  instead  the  separator is the newline
       character.  Implies -x and -L 1.
--max-procs=max-procs
-P max-procs
       Run up to max-procs processes at a time; the default is 1.  If max-procs is 0, xargs will  run  as
       many  processes as possible at a time.  Use the -n option with -P; otherwise chances are that only
       one exec will be done.
This  manual  page  documents  the  GNU  version  of  xargs.   xargs reads items from the standard input,
delimited by blanks (which can be protected with double or single quotes or a backslash) or newlines, and
executes  the  command  (default  is  /bin/echo) one or more times with any initial-arguments followed by
items read from standard input.  Blank lines on the standard input are ignored.
Commands separated  by  a ; are executed sequentially; the shell waits for each command to terminate in turn.  The
return status is the exit status of the last command executed.
source manpages: findgrepxargs