YouTipFunc Mail Ezmlm_Hash
## PHP ezmlm_hash() Function
The `ezmlm_hash()` function is a built-in PHP function used to calculate the hash value of an email address. This hash value is specifically formatted for use with **EZMLM** (Easy Mailing List Manager) when storing and managing mailing lists in a MySQL database.
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## Definition and Usage
EZMLM is an easy-to-use, high-speed mailing list manager designed to work with the qmail mail transfer agent. When storing subscriber information in a MySQL database, EZMLM uses a specific hashing algorithm to index and retrieve email addresses efficiently.
The `ezmlm_hash()` function takes an email address as a string argument and returns an integer representing its EZMLM-compatible hash value.
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## Syntax
```php
int ezmlm_hash ( string $addr )
```
### Parameter Values
| Parameter | Type | Description |
| :--- | :--- | :--- |
| `addr` | String | The email address that you want to hash. |
### Return Value
* Returns an **integer** representing the hash value of the provided email address.
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## Code Examples
### Example 1: Basic Usage
The following example demonstrates how to calculate and display the EZMLM hash value for a specific email address.
```php
```
### Example 2: Using the Hash in a MySQL Query
In a practical application, you would use this hash to query or insert subscriber records in an EZMLM MySQL database.
```php
```
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## Considerations and Best Practices
* **Platform Compatibility:** The `ezmlm_hash()` function is part of the PHP Mail extension. It is specifically designed for systems running EZMLM alongside qmail and MySQL.
* **Deprecation Notice:** As of PHP 7.4.0, the Mail extension (including `ezmlm_hash()`) is deprecated, and it has been **removed** in PHP 8.0.0. If you are developing modern applications or upgrading to PHP 8+, you should implement the hashing algorithm manually in PHP if you still need to interface with legacy EZMLM databases.
### Manual PHP Implementation (for PHP 8+)
If you are using PHP 8.0 or higher, you can replicate the behavior of `ezmlm_hash()` using the following custom function:
```php
function custom_ezmlm_hash($addr) {
$addr = strtolower($addr);
$h = 5381;
for ($i = 0; $i < strlen($addr); $i++) {
// (h * 33) + ord(c)
$h = (($h << 5) + $h) ^ ord($addr[$i]);
}
// Return a 32-bit signed integer hash
return $h & 0x7FFFFFFF;
}
```