CODEWITHSUNDEEP
phpregex
James
James

Reputation: 262

PHP regex random pattern of 5 characters

I am trying to check a license key with a pattern of 5 groups of 5 random letters separated by "-". I would like to verify the following: each group consists of 5 letters, each group does not contact certain letters, and all of the groups are capital letters. I know I can do this with the following, but I believe there is an easier method with a possible single regex expression:

$testKey = 'ASDFG-ASDFG-ASDFG-ASDFG-ASDFG';
$testKeyArray = explode('-', $testKey);
$cntKey = count($testKeyArray);
if($cntKey != 5) {
    echo 'Failed';
} else {
    for($x=0;$x<$cntKey;++$x) {
        if(strlen($testKeyArray[$x]) != 5) {
            echo 'Failed';
        }
        if(preg_match("^[B]^",$testKeyArray[$x]) == 1) {
            echo 'Failed';
        }
    }
    echo 'Success';
}

Any help would be greatly appreciated.

Upvotes: 1

Views: 213

Answers (2)

user557597
user557597

Reputation:

Here is a fairly easy way. Captures and validates in one operation.

2 ways.

  • This way is the quickest for just simple class exclusions.

^(?!.*[B])([A-Z]{5})-([A-Z]{5})-([A-Z]{5})-([A-Z]{5})-([A-Z]{5})$

Expanded:

 ^                             # BOS
 (?! .* [B] )                  # Not any of these, add more
 ( [A-Z]{5} )                  # (1)
 -
 ( [A-Z]{5} )                  # (2)
 -
 ( [A-Z]{5} )                  # (3)
 -
 ( [A-Z]{5} )                  # (4)
 -
 ( [A-Z]{5} )                  # (5)
 $                             # EOS
  • This way is the quickest for complex expressions.

^((?&ltr){5})-((?&ltr){5})-((?&ltr){5})-((?&ltr){5})-((?&ltr){5})$(?(DEFINE)(?<ltr>(?![B])[A-Z]))

Expanded: 

 ^                             # BOS
 ( (?&ltr){5} )                # (1)
 -
 ( (?&ltr){5} )                # (2)
 -
 ( (?&ltr){5} )                # (3)
 -
 ( (?&ltr){5} )                # (4)
 -
 ( (?&ltr){5} )                # (5)
 $                             # EOS 

 (?(DEFINE)
      (?<ltr>                       # (6 start)
           (?! [B] )                     # Not any of these chars ahead, add more
           [A-Z]                         # Single any of A-Z
      )                             # (6 end)
 )

Upvotes: 0

Martin Konecny
Martin Konecny

Reputation: 59601

Whereas 

^\w{5}-\w{5}-\w{5}-\w{5}-\w{5}$

Will match any alphunumeric characters AND underscores, I believe you want to match just alphabetical characters:

all of the groups are capital letter

In that case use

/^[A-Z]{5}-[A-Z]{5}-[A-Z]{5}-[A-Z]{5}-[A-Z]{5}$/

Example:

$pattern = "/^[A-Z]{5}-[A-Z]{5}-[A-Z]{5}-[A-Z]{5}-[A-Z]{5}$/";
if (preg_match($pattern, "ASDFG-ASDFG-ASDFG-ASDFG-ASDFG")) {
    echo "A match was found.";
} else {
    echo "A match was not found.";
}

each group does not contact certain letters

If you want it to not contain specific letters, you will need to break up your ranges. For example, if you don't want the letter C, your range would be [A-BD-Z] instead of [A-Z]

Upvotes: 2

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