This short PHP script will create valid JSON data from Valve Data Format (VDF) data, such as items_game.txt files for TF2 and DotA 2. This allows for much greater ease in parsing the data it contains.

valve-data-format-jsonify.php

<?php
    //load VDF data either from API call or fetching from file/url
    //no matter your method, $json must contain the VDF data to be parsed
    $json = file_get_contents("items_game.txt");

    //encapsulate in braces
    $json = "{\n$json\n}";

    //replace open braces
    $pattern = '/"([^"]*)"(\s*){/';
    $replace = '"${1}": {';
    $json = preg_replace($pattern, $replace, $json);

    //replace values
    $pattern = '/"([^"]*)"\s*"([^"]*)"/';
    $replace = '"${1}": "${2}",';
    $json = preg_replace($pattern, $replace, $json);

    //remove trailing commas
    $pattern = '/,(\s*[}\]])/';
    $replace = '${1}';
    $json = preg_replace($pattern, $replace, $json);

    //add commas
    $pattern = '/([}\]])(\s*)("[^"]*":\s*)?([{\[])/';
    $replace = '${1},${2}${3}${4}';
    $json = preg_replace($pattern, $replace, $json);

    //object as value
    $pattern = '/}(\s*"[^"]*":)/';
    $replace = '},${1}';
    $json = preg_replace($pattern, $replace, $json);

    //we now have valid json which we can use and/or store it for later use
    file_put_contents("items_game.json", $json);

    /* NB: this does not allow for creation of json arrays, however.
     * if you wish to keep working with the json data in PHP, you could
     * do something like this to get an array where needed. eg. for items
     */
    $data->items_game->items = get_object_vars($data->items_game->items); //items object is now an array
?>

Works neat but i just found out a problem some league names contain the \" character to escape double quotes like
"name" "Lima Five Peru Season \"Killer\"" which causes corrupted json output

			"name": "Lima Five Peru Season \",Killer\"": "prefab",		"league": "creation_date",		"2015-08-17": "image_banner",		"econ/leagues/subscriptions_lima_five_per__sesin__killer__ingame": "image_inventory",		"econ/leagues/subscriptions_lima_five_per__sesin__killer_": "item_description",		"#DOTA_Item_Desc_Lima_Five_Peru_Season_Killer": "item_name",		"#DOTA_Item_Lima_Five_Peru_Season_Killer": "item_type_name",		"#DOTA_WearableType_Ticket": "price_info",: {
				"category_tags": "Tournaments",
				"date": "8/17/2015",
				"price": "99"
			},
			"tool": {
				"type": "league_view_pass",
				"use_string": "#ConsumeItem",
				"usage": {
					"league_id": "3572",
					"order": "2662",
					"tier": "amateur",
					"location": "southamerica"
				}
			},
			"tournament_url": "http://www.limafiveperu.com",
			"used_by_heroes": "1"
		}

by editing the replace values pattern part i've fixed this
$pattern = '/"([^"]*)"\s*"([^"](.*|\\"))"/';

		"16348": {
			"name": "Lima Five Peru Season \"Killer\"",
			"prefab": "league",
			"creation_date": "2015-08-17",
			"image_banner": "econ/leagues/subscriptions_lima_five_per__sesin__killer__ingame",
			"image_inventory": "econ/leagues/subscriptions_lima_five_per__sesin__killer_",
			"item_description": "#DOTA_Item_Desc_Lima_Five_Peru_Season_Killer",
			"item_name": "#DOTA_Item_Lima_Five_Peru_Season_Killer",
			"item_type_name": "#DOTA_WearableType_Ticket",
			"price_info": {
				"category_tags": "Tournaments",
				"date": "8/17/2015",
				"price": "99"
			},
			"tool": {
				"type": "league_view_pass",
				"use_string": "#ConsumeItem",
				"usage": {
					"league_id": "3572",
					"order": "2662",
					"tier": "amateur",
					"location": "southamerica"
				}
			},
			"tournament_url": "http://www.limafiveperu.com",
			"used_by_heroes": "1"
		}
}

hope helps.

thanks in advance

"Killer"

But this replacement creates a problem with values which contain \n

So it's better to replace encapsulated quotes with normal ones(or remove them at all) and leave the previous expression

"(.+?)"\t*"([\S\s]*?)"\s (the best for now)