LXXXVI. Regular Expression Functions (POSIX Extended)
Note:
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.
Warning |
These regular expression functions are not binary-safe. The PCRE functions are.
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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.
Example 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. */ |
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- Table of Contents
- ereg -- Regular expression match
- ereg_replace -- Replace regular expression
- eregi -- case insensitive regular expression match
- eregi_replace -- replace regular expression case insensitive
- 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