Введение
Подсказка:
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.
| Внимание |
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.
Требования
Эти функции всегда доступны.
Установка
| Внимание |
Do not change the TYPE unless you know what you are doing.
|
To enable regexp support configure PHP
--with-regex[=TYPE]. TYPE can be one of
system, apache, php. The default is to use php.
Версия PHP для
Windows 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.
Примеры
Пример 1. Regular Expression Examples <?php
// 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 $string.
ereg("abc$", $string);
// Returns true if client browser is Netscape 2, 3 or MSIE 3.
eregi("(ozilla.[23]|MSIE.3)", $HTTP_USER_AGENT);
// Places three space separated words into $regs[1], $regs[2] and $regs[3].
ereg("([[:alnum:]]+) ([[:alnum:]]+) ([[:alnum:]]+)", $string, $regs);
// Put a <br /> tag at the beginning of $string.
$string = ereg_replace("^", "<br />", $string);
// Put a <br /> tag at the end of $string.
$string = ereg_replace("$", "<br />", $string);
// Get rid of any newline characters in $string.
$string = ereg_replace("\n", "", $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().