PHPda muntazam ifodalarning maxsus belgilarini avtomatik ekranlash

Задание 1

Berilgan satr:

php<?php
  $str = 'file.*.txt';
?>

Satrdagi muntazam ifodalarning maxsus belgilarini ekranlang.

Задание 2

Berilgan satr:

php<?php
  $str = 'price+[10-20]';
?>

Satrdagi muntazam ifodalarning maxsus belgilarini ekranlang.

Задание 3

Berilgan satr:

php<?php
  $str = 'user\name@domain.com';
?>

Satrdagi muntazam ifodalarning maxsus belgilarini ekranlang.