Returns the string $value, removing all but alphabetic and digit characters. This filter includes an option to also allow white space characters.

Returns the string $value, removing all but alphabetic characters. This filter includes an option to also allow white space characters.

Given a string containing a path to a file, this filter will return the base name of the file

Returns the string $value, removing all but digit characters.

Returns directory name component of path.

Returns the string $value, converting characters to their corresponding HTML entity equivalents where they exist.

Returns (int) $value

Returns the string $value without any newline control characters.

Expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path and return the canonicalized absolute pathname. The resulting path will have no symbolic link, '/./' or '/../' components.

Zend_Filter_RealPath will return FALSE on failure, e.g. if the file does not exist. On BSD systems Zend_Filter_RealPath doesn't fail if only the last path component doesn't exist, while other systems will return FALSE.

Returns the string $value, converting alphabetic characters to lowercase as necessary.

Returns the string $value, converting alphabetic characters to uppercase as necessary.

Returns the string $value with characters stripped from the beginning and end.

This filter returns the input string, with all HTML and PHP tags stripped from it, except those that have been explicitly allowed. In addition to the ability to specify which tags are allowed, developers can specify which attributes are allowed across all allowed tags and for specific tags only. Finally, this filter offers control over whether comments (e.g., <!-- ... -->) are removed or allowed.