My Regex returns nothing. Why?

Question

I get the content from an URL: http://money18.on.cc/js/real/hk/quote/16981_r.js

The content of this file is something like this:

M18.r_16981 = {
    "ltt": '2018/06/21 11:43',
    "np": '0.050',
    "iep": '0.000',
    "iev": '0',
    "ltp": '0.050',
    "vol": '940000',
    "tvr": '49860',



    "dyh": '0.060',
    "dyl": '0.049'
};

I want to extract the number after "vol", i.e. 940000.

And this is my php:

<?php

$content = file_get_contents("http://money18.on.cc/js/real/hk/quote/16981_r.js");

echo $content."<br>";

preg_match("/(?<=vol\": ').*(?=', \"tvr)/", $content, $output_array);

print_r(array_values($output_array));
?>

The result returns nothing. Is the Regex wrong or any other problem?

Thanks.

what kind of strange content format is this? is this meant to be JSON? do you control the content? — steros, Jun 21 '18 at 06:19
Are there more complex scenarios that you're trying to handle? Seems that `\"vol\":\s*'(\d+)'` should work just fine for what you've described. — Greg Schmidt, Jun 21 '18 at 06:19

The fourth bird · Accepted Answer · 2018-06-21T06:18:53.530

1

In your positive lookahead (?= you could replace the whitespace with \s* to match zero or more (or \s+ to match one or more) whitespace characters.

(?<=vol": ').*(?=',\s*"tvr)

Regex demo

Php demo

edited Jun 21 '18 at 06:18

answered Jun 21 '18 at 06:13

The fourth bird

154,723
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if anyone just incase wants to know if it really works on the `file_get_contents` flavor https://www.tehplayground.com/PTNMZMcztkDhwm2R +1 – Kevin Jun 21 '18 at 06:30
@Ghost Awesome tip! Thank you! – The fourth bird Jun 21 '18 at 06:40

score 0 · Answer 2 · answered Jun 21 '18 at 06:23

Bit of a long shot but...

If that content is actually meant to represent JSON and you have control over it: get it into proper format as it is much easier and secure to get the data you want out of it then.

$jsonString = <<<JSON
{
    "ltt": "2018/06/21 11:43",
    "np": "0.050",
    "iep": "0.000",
    "iev": "0",
    "ltp": "0.050",
    "vol": "940000",
    "tvr": "49860",
    "dyh": "0.060",
    "dyl": "0.049"
}
JSON;

$jsonAsArray = json_decode($jsonString, true);
var_dump($jsonAsArray['vol']);

My Regex returns nothing. Why?

2 Answers2