preg_match matching pattern with asterisk (*) in it [duplicate]

Question

preg_match('/te**ed/i', 'tested', $matches);

gives me the following error:

ERROR: nothing to repeat at offset 3

What do I do to allow the pattern to actually contain *?

Answer 1

To use literal asterisks you have to escape them with backslashes. To match the literal te**ed you would use an expression like this:

preg_match('/te\*\*ed/i', 'tested', $matches); // no match (te**ed != tested)

But I doubt this is what you wanted. If you mean, match any character, you need to use .:

preg_match('/te..ed/is', 'tested', $matches); // match

If you really want any two lower case letter, then this expression:

preg_match('/te[a-z]{2}ed/i', 'tested', $matches); // match

Answer 2

Putting a backslash before any character wil tell PHP that the character should be taken as is, not as a special regex character. So:

preg_match('/te\\**ed/i', 'tested', $matches);

Answer 3

If you want to use asterisk-like search, you can use next function:

function match_string($pattern, $str)
{
  $pattern = preg_replace('/([^*])/e', 'preg_quote("$1", "/")', $pattern);
  $pattern = str_replace('*', '.*', $pattern);
  return (bool) preg_match('/^' . $pattern . '$/i', $str);
}

Example:

match_string("*world*","hello world") // returns true
match_string("world*","hello world") // returns false
match_string("*world","hello world") // returns true
match_string("world*","hello world") // returns false
match_string("*ello*w*","hello world") // returns true
match_string("*w*o*r*l*d*","hello world") // returns true