Regular Expression Functions (POSIX Extended)
Introductie
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.
Afhankelijkheden
Deze functies zijn beschikbaar als onderdeel van de standaard module die altijd beschikbaar is.
Installatie
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.
Deze functies worden automatisch ingebouwd in de windows versie van PHP. Er zijn geen extra handelingen nodig om deze functies te gebruiken.
Configuratie tijdens scriptuitvoer
Deze extensie gebruikt geen configuratie regels.
Resource types
Deze extensie maakt geen gebruik van resources.
Voorgedefinieerde constanten
Deze extensie definieert geen constanten.
Voorbeelden
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);
?>
Zie ook
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