PHP function to reverse print_r function

print_r_reverse.php

<?php
/**
 * I've published a fully-tested Composer library with type-casting. 
 * @see https://github.com/simivar/reverse-print-r
 */

/**
  * Matt: core
  * Trixor: object handling
  * lech: Windows suppport
  * simivar: null support
  *
  * @see http://php.net/manual/en/function.print-r.php
  **/
function print_r_reverse($input) {
        $lines = preg_split('#\r?\n#', trim($input));
        if (trim($lines[ 0 ]) != 'Array' && trim($lines[ 0 ]) != 'stdClass Object') {
            // bottomed out to something that isn't an array or object
            if ($input === '') {
                return null;
            }
            
            return $input;
        } else {
            // this is an array or object, lets parse it
            $match = array();
            if (preg_match("/(\s{5,})\(/", $lines[ 1 ], $match)) {
                // this is a tested array/recursive call to this function
                // take a set of spaces off the beginning
                $spaces = $match[ 1 ];
                $spaces_length = strlen($spaces);
                $lines_total = count($lines);
                for ($i = 0; $i < $lines_total; $i++) {
                    if (substr($lines[ $i ], 0, $spaces_length) == $spaces) {
                        $lines[ $i ] = substr($lines[ $i ], $spaces_length);
                    }
                }
            }
            $is_object = trim($lines[ 0 ]) == 'stdClass Object';
            array_shift($lines); // Array
            array_shift($lines); // (
            array_pop($lines); // )
            $input = implode("\n", $lines);
            $matches = array();
            // make sure we only match stuff with 4 preceding spaces (stuff for this array and not a nested one)
            preg_match_all("/^\s{4}\[(.+?)\] \=\> /m", $input, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
            $pos = array();
            $previous_key = '';
            $in_length = strlen($input);
            // store the following in $pos:
            // array with key = key of the parsed array's item
            // value = array(start position in $in, $end position in $in)
            foreach ($matches as $match) {
                $key = $match[ 1 ][ 0 ];
                $start = $match[ 0 ][ 1 ] + strlen($match[ 0 ][ 0 ]);
                $pos[ $key ] = array($start, $in_length);
                if ($previous_key != '') {
                    $pos[ $previous_key ][ 1 ] = $match[ 0 ][ 1 ] - 1;
                }
                $previous_key = $key;
            }
            $ret = array();
            foreach ($pos as $key => $where) {
                // recursively see if the parsed out value is an array too
                $ret[ $key ] = print_r_reverse(substr($input, $where[ 0 ], $where[ 1 ] - $where[ 0 ]));
            }
            
            return $is_object ? (object)$ret : $ret;
        }
    }

if (trim($lines[ 0 ]) != 'Array' && trim($lines[ 0 ] != 'stdClass Object')) {
has a bug, it should be
if (trim($lines[ 0 ]) != 'Array' && trim($lines[ 0 ]) != 'stdClass Object') {

Cool for putting it here :)

@MagicTrixor: fixed

Thanks for sharing, what is the license on this code? Also, any interest in turning it into a composer package (I'm willing to set that up if needed).

@digitalowlnyc it was first posted on php.net note's section on print_r. From what I gather all notes are shared on the same license as PHP documentation (see here), so it's CC BY 3.0.

I don't think there is a composer package for that but I'll try to set something up soon and refactor it a little. If you feel like you need it now feel free to publish it yourself as it is CC BY 3.0.

you can use

if (trim($lines[ 0 ]) != 'Array' && !preg_match('/^\S+?\ Object$/',trim($lines[ 0 ])))

to support objects other than stdClass Object, for example it fixed this:

Replay Object
(
    [id] => 1106
    [date] => 2020-02-22 09:57:28
    [json] => Array
        (
            [id] => CForEIS28JPUV
            [name] => Kontor
            [type] => Office
            [event] => Update
            [subtype] => Office
            [customerId] => S3
        )

    [url] => http://www.eS322
)

@divinity76 could you provide the source code of Replay class? It will make nice test-case.

nothing more fancy than

class Replay
{

    public $id;

    public $date;

    public $json;
}

.. the url-attribute was added post-construction

I've published a fully-tested Composer library with type-casting. See simivar/reverse-print-r if you want to use that.

/cc @divinity76 @digitalowlnyc