Returns a valid regular expression which will match string, ignoring case. This expression is string with each character converted to a bracket expression this bracket expression contains that character's uppercase and lowercase form if applicable, otherwise it contains the original character twice.

ד 1. Regular Expression Examples

The special regular expression characters are

For even more powerful string handling and manipulating functions take a look at the POSIX regular expression functions and the Perl compatible regular expression functions.

Returns the length of the given expression.

PCRE provides some extensions to the Perl regular expression facilities

enable mbregex Enable regular expression functions with multibyte character support.

These regular expression functions are not binary safe. The PCRE functions are.

Write the given expression to the trace log. Doubtful that the browser plugin does anything with this.

They have made it clear that when it comes to free expression, their priorities lie on the side of surrender.

Searches subject for all matches to the regular expression given in pattern and puts them in matches in the order specified by flags.

These functions all manipulate strings in various ways. Some more specialized sections can be found in the regular expression and URL handling sections.

If this flag is set, parenthesized expression in the delimiter pattern will be captured and returned as well. This flag was added for 4.0.5.

ע PHP also supports regular expressions using a Perl compatible syntax using the PCRE functions. Those functions support non greedy matching, assertions, conditional subpatterns, and a number of other features not supported by the POSIX extended regular expression syntax.

蛁 This function returns SUCCESS for success or FAILURE for failure. Be warned that you must explicitly compare the return value with SUCCESS or FAILURE because of the underlying values of those constants. A simple boolean expression will not be interpreted as you intended.

ע Due a limitation in the current Zend Engine it is not possible to pass a constant modifier like NULL directly as a parameter to a function which expects this parameter to be passed by reference. Instead use a temporary variable or an expression with the leftmost member being a temporary variable

蛁 Due a limitation in the current Zend Engine it is not possible to pass a constant modifier like NULL directly as a parameter to a function which expects this parameter to be passed by reference. Instead use a temporary variable or an expression with the leftmost member being a temporary variable

The handling of a backslash followed by a digit other than 0 is complicated. Outside a character class, PCRE reads it and any following digits as a decimal number. If the number is less than 10, or if there have been at least that many previous capturing left parentheses in the expression, the entire sequence is taken as a back reference. A description of how this works is given later, following the discussion of parenthesized subpatterns.