Request URL containing $ doesn't work well with PHP - cURL

[honeyyadav]

Short Explanation

When I am generating PHP - cURL code from a postman request with URL containing a $ sign followed by a letter or underscore (for example $firstName, $_address, $LastName), then the code generated by postman doesn't work. This is because PHP treats them as variable name (but they are not variable name(s) in this case).

Example

My request URL is : -

> http://example.com/path?$filter=name eq John

The code generated by postman : -

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "http://example.com/path?$filter=name%20eq%20John",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;

The above code will not work as PHP will treat $filter as a variable name. To solve this problem we need to put a \ (backslash) before $filter like this : -

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "http://example.com/path?\$filter=name%20eq%20John",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;

And now it will work flawlessly.

Postman version used: v7.26.0

[erdemkose]

Instead of escaping $ characters, replacing double quotes(") with single quotes(') would be a simpler and cleaner solution. PHP does not look for variables in single-quoted strings.

[shellstrom]

I'm not entirely sure this is the exact same thing, but I'm errors from an API when I use the PHP - cURL option and the postfields look like this. I can run this no problem with bash curl export equivalent in Postman, but for some reason this isn't working out of the box with the PHP - cURL option.
However, @honeyyadav 's suggestion worked out for me, by prepending every $ with a \, resulting in \$...

CURLOPT_POSTFIELDS` =>"[\r\n    {\r\n        \"name\": null,\r\n        \"variables\": {\r\n            \"postId\": \"502\",\r\n            \"next\": \"520\",\r\n            \"previous\": null,\r\            \"start\": 50,\r\n            \"end\": null\r\n        },\r\n        \"query\": \"query ($postId: ID!, $next: String, $previous: String, $start: Int, $end: Int) {\\n  posts: article(id: $postId) {...

[webholik]

Fixed by #352