Decomposing a string into words separared by spaces, ignoring spaces within quoted strings, and considering ( and ) as words

user_19199595 0
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How can I explode the following string:

+test +word any -sample (+toto +titi "generic test") -column:"test this" (+data id:1234)

into

Array('+test', '+word', 'any', '-sample', '(', '+toto', '+titi', '"generic test"', ')', '-column:"test this"', '(', '+data', 'id:1234', ')')

I would like to extend the boolean fulltext search SQL query, adding the feature to specify specific columns using the notation column:value or column:"valueA value B".

How can I do this using preg_match_all($regexp, $query, $result), i.e., what is the correct regular expression to use?

Or more generally, what would be the most appropriate regular expression to decompose a string into words not containing spaces, where spaces within text between quotes is not considered spaces, for the sake of defining a word, and ( and ) are considered words, independent of being surrounded by spaces. For example xxx"yyy zzz" should be considered a single world. And (aaa) should be three words (, aaa and ).

I have tried something like /"(?:\\\\.|[^\\\\"])*"|\S+/, but with limited/no success.

Can anybody help?

matching php regex
2 Answers
user_37832430

If you want to match the various parts using alternations:

(?:[^\s()":]*:)?"[^"]+"|[^\s()]+|[()]

Explanation

  • (?: Non capture group to match as a whole part
    • [^\s()":]*: Match optional non whitespace chars other than ( ) " : and then match :
  • )? Close the non capture group and make it optional
  • "[^"]+" Match from an opening double quote till closing double quote
  • | Or
  • [^\s()]+ Match 1+ non whitespace chars other than ( or )
  • | Or
  • [()] Match either ( or )

Regex demo | PHP demo

Example code

$re = '/(?:[^\s()":]*:)?"[^"]+"|[^\s()]+|[()]/';
$str = '+test +word any -sampe (+toto +titi "generic test") -column:"test this" (+data id:1234)';
preg_match_all($re, $str, $matches);
print_r($matches[0]);

Output

Array
(
    [0] => +test
    [1] => +word
    [2] => any
    [3] => -sampe
    [4] => (
    [5] => +toto
    [6] => +titi
    [7] => "generic test"
    [8] => )
    [9] => -column:"test this"
    [10] => (
    [11] => +data
    [12] => id:1234
    [13] => )
)
user_54249880
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