Dump PHP variables into the error log instead of the page when debugging

error_dump.php

<?php

    /**
     * Dump a variable to error_log instead of the main page
     *
     * To do debugging, it's often preferable to stick output into the
     * error log rather than the main page, in case you might forget to remove
     * a statement (it does happen) - but you can't do `var_dump()` or
     * `print_r()` to output, or at least you couldn't before. This will get
     * the output of those functions and send them to error_log(), reformatted
     * so that each line gets its own output, since many configurations will
     * result in literal newlines being converted to "\n" in the logs,
     * resulting in messy output. Each line is also prefixed with a string:
     *
     *   "DUMP from $file:$line:"
     *
     * This way you can both easily grep for the output you're looking for, as
     * well as quickly find where you've put in a debugging statement, again
     * in case you've left it in by accident.
     *
     * The default is to use `var_dump()`, as it is far more verbose than
     * `print_r()`, though the output isn't as clean. If you're trying to
     * debug a particular object and don't care to know the difference between
     * various `FALSE`-y values, and other information such as string length,
     * you can pass a `true` value after your variable, and the function will
     * switch to using `print_r()` instead.
     *
     * @param mixed $var The variable or expression to dump
     * @param boolean $print (optional) Whether to dump with print_r()
     * @return void
     */
    function error_dump($var, $printr = false) {
        ob_start();
        if ($printr) {
            print_r($var);
        }
        else {
            var_dump($var);
        }
        
        $output   = explode("\n", ob_get_clean());
        $trace    = debug_backtrace();
        $location = $trace[0]['file'] . ':' . $trace[0]['line'];
        
        foreach ($output as $x => $line) {
            error_log("DUMP from $location: $line");
        }
    }

?>