PHP3 Manual
PrevChapter 2. PHP3 featuresNext

Regular expressions

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.

Example 2-4. 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 $regs[3]. */
ereg_replace("^","<BR>",$string); /* Put a <BR> tag at the beginning of $string. */
ereg_replace("$","<BR>",$string); /* Put a <BR> tag at the end of $string. */
ereg_replace("\n","",$string); /* Get rid of any carriage return characters in $string. */

PrevHomeNext
Database supportUpError handling