XCVII. Regular Expression Functions (POSIX Extended)

Introduktion

Vink: 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.

Advarsel

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.

Systemkrav

Ingen eksterne libraries er nødvendige for at kompilere denne udvidelse.

Installation

Advarsel

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.

Windows versionen af PHP har indbygget support for denne udvidelse. Du behøver ikke indsætte ekstra udvidelser for at bruge disse funktioner.

Runtime Konfiguration

Denne udvidelse har intet konfigurations-direktiv defineret i php.ini.

Ressourcetyper

Denne udvidelse har ingen ressourcetyper defineret.

Foruddefinerede Konstanter

Denne udvidelse har ingen konstanter.

Eksempler

Eksempel 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);
?>

Se også

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().

Indholdsfortegnelse
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