$re = '/(?|(?:\G(?!\A)(?<=\|)|^\|\h*\[x\]\h*\|)\h*\K([^|\n]+)(?<=\S)\h*\||\[x]\h*\K([^|\s!]+(?:\h*[^|\s]+)*))|
(?|(?:\G(?!\A)\||^\|\h*\[x]\h*!\h*\|)\h*\K([^|\n]+)(?<=\S)\h*|\[x]\h*!\h*\K([^|\s]+(?:\h*[^|\s]+)*))/mx';
$str = 'Test cases where it should match.
- [x] Example task. | Task ends. [x] Another task.
- [x] ! Example task. | This ends. [x] ! Another task.
- [x] Example task! | Task ends. [x] Another task!
- [x] ! Example task! | This ends. [x] ! Another task!
This is a sentence. [x] Task is here.
Other text. Another [x] ! Task is here.
Must not match in the table.
| | Task name | Plan | Actual | File |
| :---- | :-------------| :---------: | :---------: | :------------: |
| [x] | Task example. | 08:00-08:45 | 08:00-09:00 | [[task-one]] |
| [x] ! | Task example. | 08:00-08:45 | 08:00-09:00 | [[task-one]] |
Groups expected:
$1: all text after [x]
$2: all text after [x] !
Regex for each group:
$1: [^\\|\\s]\\s*\\[x\\]\\s*\\K[^!|\\n]*
$2: [^\\|\\s]\\s*\\[x\\]\\s*\\!\\s*\\K[^|\\n]*
With the not-capturing group applied:
$1: (?:[^\\|\\s]\\s*\\[x\\]\\s*\\K[^!|\\n]*)
$2: (?:[^\\|\\s]\\s*\\[x\\]\\s*\\!\\s*\\K[^|\\n]*)
The combined expression:
(?:[^\\|\\s]\\s*\\[x\\]\\s*\\K([^!|\\n]*))|(?:[^\\|\\s]\\s*\\[x\\]\\s*\\!\\s*\\K([^|\\n]*))';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php