Hacky way to use shlex.split in PHP

hack_shlex.php

<?php
/**
 * Hacks around the fact that there isn't a good shell-style argument lexer
 * for PHP by using the Python one.
 * One argument: the line to parse as a shell line.
 * Returns: An array such that:
 *          'foo --bar baz\ foo "/bar/foo man/quux"' → ['foo', '--bar', 'baz foo', '/bar/foo man/quux']
 * Caveat: no error handling. Depends on /usr/bin/python3 being python. It's horrible.
 */
function hack_shlex($str) {
  // Set up file descriptors for the python program
  $dspec = [
    0 => ['pipe', 'r'],
    1 => ['pipe', 'w'],
    2 => ['file', '/dev/null', 'a']
  ];

  // Opens Python, it runs the following program:
  //
  // from shlex import split
  // from json import dumps
  // print(dumps(split(input())))
  //
  // It does exactly 4 things:
  // 1. Reads a line from the standard input
  // 2. Uses the Python shlex module to parse the line into shell arguments
  // 3. Encodes the resulting array of strings into JSON
  // 4. Prints that JSON to stdout, to be read from the PHP side.
  $ph = proc_open("/usr/bin/python3 -c 'from shlex import split; from json import dumps; print(dumps(split(input())));'", $dspec, $pipes);

  // Writes the string to lex to the python program
  fwrite($pipes[0], $str);

  // Close the write stream as we've written what we needed
  fclose($pipes[0]);

  // Read the result from the Python program
  $result = stream_get_contents($pipes[1]);

  // No need for this now
  fclose($pipes[1]);

  // Python's done its job now
  proc_close($ph);

  // Decode json and return the parsed shell line
  return json_decode(trim($result));
}