XC. Regular Expression Functions (POSIX Extended)


Замечание: 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.


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

Regular expressions are used for complex string manipulation in PHP. The functions that support regular expressions are:

These functions all take a regular expression string as their first argument. PHP uses the POSIX extended regular expressions as defined by POSIX 1003.2. For a full description of POSIX regular expressions see the regex man pages included in the regex directory in the PHP distribution. It's in manpage format, so you'll want to do something along the lines of man /usr/local/src/regex/regex.7 in order to read it.


Эти функции всегда доступны.


To enable regexp support configure PHP --with-regex[=TYPE]. TYPE can be one of system, apache, php. The default is to use php.

Замечание: Do not change the TYPE unless you know what you are doing.

Версия PHP для Windows-совместимых платформ имеет встроенную поддержку данного расширения. Это означает, что для использования данных функций не требуется загрузка никаких дополнительных расширений.

Настройка во время выполнения

Данное расширение не определяет никакие директивы конфигурации в php.ini.

Типы ресурсов

Данное расширение не определяет никакие типы ресурсов.

Предопределенные константы

Данное расширение не определяет никакие константы.


Пример 1. Regular Expression Examples

ereg ("abc", $string);            
/* Returns true if "abc"
   is found anywhere in $string. */

ereg ("^abc", $string);
/* Returns true if "abc"
   is found at the beginning of $string. */

ereg ("abc$", $string);
/* Returns true if "abc"
   is found at the end of $string. */

eregi ("(ozilla.[23]|MSIE.3)", $HTTP_USER_AGENT);  
/* Returns true if client browser
   is Netscape 2, 3 or MSIE 3. */

ereg ("([[:alnum:]]+) ([[:alnum:]]+) ([[:alnum:]]+)", $string,$regs); 
/* Places three space separated words
   into $regs[1], $regs[2] and $regs[3]. */

$string = ereg_replace ("^", "<br />", $string); 
/* Put a <br /> tag at the beginning of $string. */
$string = ereg_replace ("$", "<br />", $string); 
/* Put a <br /> tag at the end of $string. */

$string = ereg_replace ("\n", "", $string);
/* Get rid of any newline
   characters in $string. */

Смотрите также

For regular expressions in Perl-compatible syntax have a look at the PCRE functions. The simpler shell style wildcard pattern matching is provided by fnmatch().

ereg_replace -- Replace regular expression
ereg -- Regular expression match
eregi_replace -- replace regular expression case insensitive
eregi -- case insensitive regular expression match
split -- split string into array by regular expression
spliti --  Split string into array by regular expression case insensitive
sql_regcase --  Make regular expression for case insensitive match