Regular Expression Functions (POSIX Extended)
簡介
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. 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.
需求
要編譯本擴充功能無需外部函式庫。
安裝
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.
PHP 的 Windows 版本已經內置該擴充功能的支援。無需載入任何附加擴充功能即可使用這些函式。
執行時期設定
本擴充功能在 php.ini 中未定義任何設定選項。
資源類型
本擴充功能未定義任何資源類型。
預設常數
本擴充功能未定義任何常數。
範例
Example#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)", $_SERVER["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);
?>
參見
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().
Table of Contents
- 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