Attempts to convert a JSON to CSV

json2csv.php

<?php

if (count($argv) != 3) {
  error_log("Pass input_file_path output_file_path");
  exit;
}
$input_file_path = $argv[1];
$output_file_path = $argv[2];
$json_str = file_get_contents($input_file_path);

$json = json_decode($json_str, true);

function json2csv(array $json, $output_file_path) {
  $f = fopen($output_file_path, "w");
  $keys = array_keys($json[0]);
  for ($i = 0; $i < count($json); $i++) {
	$record = $json[$i];
	$row = array();
	for ($j = 0; $j < count($keys); $j++) {
	  $row[] = $record[$keys[$j]];
	}
	fputcsv($f, $row);
  }
  fclose($f);
}

$int_index_json = array_values($json);

if ($json == $int_index_json) {
  json2csv($json, $output_file_path);
}
elseif (count($json) > 0 && is_array($int_index_json[0]) && $int_index_json[0] == array_values($int_index_json[0])) {
  json2csv($int_index_json[0], $output_file_path);
}
else {
  error_log("unsupported json format for csv conversion");
}