There are a few PHP native functions that should be avoided.
| extension | Dropped in version | Alternative |
|---|---|---|
| dbase | 5.3 | Abandoned |
| ereg | 5.3 | pcre |
| fbsql | 5.3 | Abandoned |
| fdf | 5.3 | pecl/fdf |
| mhash | 5.3 | hash |
| ming | 5.3 | pecl/ming |
| msql | 5.3 | Abandoned |
| mssql | 5.3 | Use SQLSRV from Microsoft |
| mysql | 5.5 | Deprecated only. Use pdo or mysqli |
| ncurses | 5.3 | pecl/ncurses |
| sqlite | 5.4 | sqlite3 |
| sybase | 5.3 | pecl/sybase_ct |
Using any of the extensions mentioned above will trigger a warning. Usage include constants, functions, classes, interfaces or directives, if any.