strip_tags(3) [php man page]
STRIP_TAGS(3) 1 STRIP_TAGS(3) strip_tags - Strip HTML and PHP tags from a string SYNOPSIS
string strip_tags (string $str, [string $allowable_tags]) DESCRIPTION
This function tries to return a string with all NULL bytes, HTML and PHP tags stripped from a given $str. It uses the same tag stripping state machine as the fgetss(3) function. PARAMETERS
o $str - The input string. o $allowable_tags - You can use the optional second parameter to specify tags which should not be stripped. Note HTML comments and PHP tags are also stripped. This is hardcoded and can not be changed with $allowable_tags. Note This parameter should not contain whitespace. strip_tags(3) sees a tag as a case-insensitive string between < and the first whitespace or >. Note In PHP 5.3.4 and later, you will also need to include the self-closing XHTML tag to strip these from $str. For example, to strip both <br> and <br/>, you should use: <?php strip_tags($input, '<br><br/>'); ?> RETURN VALUES
Returns the stripped string. CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 5.3.4 | | | | | | | strip_tags(3) no longer strips self-closing XHTML | | | tags unless the self-closing XHTML tag is also | | | given in $allowable_tags. | | | | | 5.0.0 | | | | | | | strip_tags(3) is now binary safe. | | | | +--------+---------------------------------------------------+ EXAMPLES
Example #1 strip_tags(3) example <?php $text = '<p>Test paragraph.</p><!-- Comment --> <a href="#fragment">Other text</a>'; echo strip_tags($text); echo " "; // Allow <p> and <a> echo strip_tags($text, '<p><a>'); ?> The above example will output: Test paragraph. Other text <p>Test paragraph.</p> <a href="#fragment">Other text</a> NOTES
Warning Because strip_tags(3) does not actually validate the HTML, partial or broken tags can result in the removal of more text/data than expected. Warning This function does not modify any attributes on the tags that you allow using $allowable_tags, including the style and onmouseover attributes that a mischievous user may abuse when posting text that will be shown to other users. Note Tag names within the input HTML that are greater than 1023 bytes in length will be treated as though they are invalid, regardless of the $allowable_tags parameter. SEE ALSO
htmlspecialchars(3). PHP Documentation Group STRIP_TAGS(3)
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PREG_MATCH_ALL(3) 1 PREG_MATCH_ALL(3) preg_match_all - Perform a global regular expression match SYNOPSIS
int preg_match_all PREG_PATTERN_ORDER (string $pattern, string $subject, [array &$matches], [int $flags], [int $offset]) DESCRIPTION
Searches $subject for all matches to the regular expression given in $pattern and puts them in $matches in the order specified by $flags. After the first match is found, the subsequent searches are continued on from end of the last match. PARAMETERS
o $pattern - The pattern to search for, as a string. o $subject - The input string. o $matches - Array of all matches in multi-dimensional array ordered according to $flags. o $flags - Can be a combination of the following flags (note that it doesn't make sense to use PREG_PATTERN_ORDER together with PREG_SET_ORDER): o PREG_PATTERN_ORDER - Orders results so that $matches[0] is an array of full pattern matches, $matches[1] is an array of strings matched by the first parenthesized subpattern, and so on. <?php preg_match_all("|<[^>]+>(.*)</[^>]+>|U", "<b>example: </b><div align=left>this is a test</div>", $out, PREG_PATTERN_ORDER); echo $out[0][0] . ", " . $out[0][1] . " "; echo $out[1][0] . ", " . $out[1][1] . " "; ?> The above example will output: <b>example: </b>, <div align=left>this is a test</div> example: , this is a test So, $out[0] contains array of strings that matched full pattern, and $out[1] contains array of strings enclosed by tags. o PREG_SET_ORDER - Orders results so that $matches[0] is an array of first set of matches, $matches[1] is an array of second set of matches, and so on. <?php preg_match_all("|<[^>]+>(.*)</[^>]+>|U", "<b>example: </b><div align="left">this is a test</div>", $out, PREG_SET_ORDER); echo $out[0][0] . ", " . $out[0][1] . " "; echo $out[1][0] . ", " . $out[1][1] . " "; ?> The above example will output: <b>example: </b>, example: <div align="left">this is a test</div>, this is a test o PREG_OFFSET_CAPTURE - If this flag is passed, for every occurring match the appendant string offset will also be returned. Note that this changes the value of $matches into an array where every element is an array consisting of the matched string at offset 0 and its string offset into $subject at offset 1. If no order flag is given, PREG_PATTERN_ORDER is assumed. o $offset - Normally, the search starts from the beginning of the subject string. The optional parameter $offset can be used to specify the alternate place from which to start the search (in bytes). Note Using $offset is not equivalent to passing substr($subject, $offset) to preg_match_all(3) in place of the subject string, because $pattern can contain assertions such as ^, $ or (?<=x). See preg_match(3) for examples. RETURN VALUES
Returns the number of full pattern matches (which might be zero), or FALSE if an error occurred. CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 5.4.0 | | | | | | | The $matches parameter became optional. | | | | | 5.3.6 | | | | | | | Returns FALSE if $offset is higher than $subject | | | length. | | | | | 5.2.2 | | | | | | | Named subpatterns now accept the syntax | | | (?<name>) and (?'name') as well as (?P<name>). | | | Previous versions accepted only (?P<name>). | | | | +--------+---------------------------------------------------+ EXAMPLES
Example #1 Getting all phone numbers out of some text. <?php preg_match_all("/(? (d{3})? )? (?(1) [-s] ) d{3}-d{4}/x", "Call 555-1212 or 1-800-555-1212", $phones); ?> Example #2 Find matching HTML tags (greedy) <?php // The \2 is an example of backreferencing. This tells pcre that // it must match the second set of parentheses in the regular expression // itself, which would be the ([w]+) in this case. The extra backslash is // required because the string is in double quotes. $html = "<b>bold text</b><a href=howdy.html>click me</a>"; preg_match_all("/(<([w]+)[^>]*>)(.*?)(</\2>)/", $html, $matches, PREG_SET_ORDER); foreach ($matches as $val) { echo "matched: " . $val[0] . " "; echo "part 1: " . $val[1] . " "; echo "part 2: " . $val[2] . " "; echo "part 3: " . $val[3] . " "; echo "part 4: " . $val[4] . " "; } ?> The above example will output: matched: <b>bold text</b> part 1: <b> part 2: b part 3: bold text part 4: </b> matched: <a href=howdy.html>click me</a> part 1: <a href=howdy.html> part 2: a part 3: click me part 4: </a> Example #3 Using named subpattern <?php $str = <<<FOO a: 1 b: 2 c: 3 FOO; preg_match_all('/(?P<name>w+): (?P<digit>d+)/', $str, $matches); /* This also works in PHP 5.2.2 (PCRE 7.0) and later, however * the above form is recommended for backwards compatibility */ // preg_match_all('/(?<name>w+): (?<digit>d+)/', $str, $matches); print_r($matches); ?> The above example will output: Array ( [0] => Array ( [0] => a: 1 [1] => b: 2 [2] => c: 3 ) [name] => Array ( [0] => a [1] => b [2] => c ) [1] => Array ( [0] => a [1] => b [2] => c ) [digit] => Array ( [0] => 1 [1] => 2 [2] => 3 ) [2] => Array ( [0] => 1 [1] => 2 [2] => 3 ) ) SEE ALSO
PCRE Patterns, preg_quote(3), preg_match(3), preg_replace(3), preg_split(3), preg_last_error(3). PHP Documentation Group PREG_MATCH_ALL(3)