preg_last_error
Here is a way to match everything on the page, performing an action for each match as you go. I had used this idiom in other languages, where its use is customary, but in PHP it seems to be not quite as common.
<?php
function custom_preg_match_all($pattern, $subject)
{
$offset = 0;
$match_count = 0;
while(preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE, $offset))
{
// Increment counter
$match_count++;
// Get byte offset and byte length (assuming single byte encoded)
$match_start = $matches[0][1];
$match_length = strlen(matches[0][0]);
// (Optional) Transform $matches to the format it is usually set as (without PREG_OFFSET_CAPTURE set)
foreach($matches as $k => $match) $newmatches[$k] = $match[0];
$matches = $new_matches;
// Your code here
echo "Match number $match_count, at byte offset $match_start, $match_length bytes long: ".$matches[0]."\r\n";
// Update offset to the end of the match
$offset = $match_start + $match_length;
}
return $match_count;
}
?>
Note that the offsets returned are byte values (not necessarily number of characters) so you'll have to make sure the data is single-byte encoded. (Or have a look at paolo mosna's strByte function on the strlen manual page).
I'd be interested to know how this method performs speedwise against using preg_match_all and then recursing through the results.
preg_match_all
(PHP 4, PHP 5)
preg_match_all — 繰り返し正規表現検索を行う
説明
int preg_match_all
( string $pattern
, string $subject
, array &$matches
[, int $flags
[, int $offset
]] )
subject を検索し、 pattern に指定した正規表現にマッチした すべての文字列を、flags で指定した 順番で、matches に代入します。
正規表現にマッチすると、そのマッチした文字列の後から 検索が続行されます。
パラメータ
- pattern
-
検索するパターンを表す文字列。
- subject
-
入力文字列。
- matches
-
マッチしたすべての内容を含む、 flags で指定した形式の多次元配列。
- flags
-
以下のフラグの組み合わせ (PREG_PATTERN_ORDER を PREG_SET_ORDER と組み合わせて使用することは 無意味ですので注意してください)。
- PREG_PATTERN_ORDER
-
$matches[0] はパターン全体にマッチした文字列の配列、 $matches[1] は第 1 のキャプチャ用サブパターンにマッチした文字列の配列、 といった順番となります。
<?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] . "\n";
echo $out[1][0] . ", " . $out[1][1] . "\n";
?>上の例の出力は以下となります。
<b>example: </b>, <div align=left>this is a test</div> example: , this is a test
$out[0] はパターン全体にマッチした文字列の配列を有しており、 $out[1] はタグで囲まれた文字列の配列を有しています。
- PREG_SET_ORDER
-
$matches[0] は 1 回目のマッチングでキャプチャした値の配列、 $matches[1] は 2 回目のマッチングでキャプチャした値の配列、 といった順序となります。
<?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] . "\n";
echo $out[1][0] . ", " . $out[1][1] . "\n";
?>上の例の出力は以下となります。
<b>example: </b>, example: <div align="left">this is a test</div>, this is a test
- PREG_OFFSET_CAPTURE
-
このフラグを設定した場合、各マッチに対応する文字列のオフセットも返されます。 これにより、返り値は配列となり、配列の要素 0 はマッチした文字列、 要素 1 は subject における マッチした文字列のオフセット値となることに注意してください。
flags を指定しない場合は、 PREG_PATTERN_ORDER が指定されたことになります。
- offset
-
通常、検索は対象文字列の先頭から開始されます。 オプションのパラメータ offset を使用して 検索の開始位置を (バイト単位で) 指定することも可能です。
注意: offset を用いるのと、 substr($subject, $offset) を preg_match_all()の対象文字列として指定するのとは 等価ではありません。 これは、pattern には、 ^, $ や (?<=x) のような言明を含めることができるためです。 これに関する例については、 preg_match() を参照してください。
返り値
パターンがマッチした総数を返します（ゼロとなる可能性もあります）。 または、エラーが発生した場合に FALSE を返します。
変更履歴
| バージョン | 説明 |
|---|---|
| 4.3.3 | パラメータ offset が追加されました。 |
| 4.3.0 | フラグ PREG_OFFSET_CAPTURE が追加されました。 |
例
例1 テキストからすべての電話番号を得る
<?php
preg_match_all("/\(? (\d{3})? \)? (?(1) [\-\s] ) \d{3}-\d{4}/x",
"Call 555-1212 or 1-800-555-1212", $phones);
?>
例2 HTML タグにマッチするものを見付ける（貪欲）
<?php
// \\2 は後方参照の例。これは、pcre に正規表現中の括弧の 2 番目の
// 組、つまりこの場合は ([\w]+)、にマッチする。文字列が二重引用符で
// 括られているため、バックスラッシュの追加が必要。
$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] . "\n";
echo "part 1: " . $val[1] . "\n";
echo "part 2: " . $val[3] . "\n";
echo "part 3: " . $val[4] . "\n\n";
}
?>
上の例の出力は以下となります。
matched: <b>bold text</b> part 1: <b> part 2: bold text part 3: </b> matched: <a href=howdy.html>click me</a> part 1: <a href=howdy.html> part 2: click me part 3: </a>
例3 名前つきサブパターンの使用法
<?php
$str = <<<FOO
a: 1
b: 2
c: 3
FOO;
preg_match_all('/(?<name>\w+): (?<digit>\d+)/', $str, $matches);
print_r($matches);
?>
上の例の出力は以下となります。
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 ) )
add a note
User Contributed Notespreg_match_all
MonkeyMan
07-Oct-2008 01:25
07-Oct-2008 01:25
sledge NOSPAM
19-Jun-2008 01:46
19-Jun-2008 01:46
Perhaps you want to find the positions of all anchor tags. This will return a two dimensional array of which the starting and ending positions will be returned.
<?php
function getTagPositions($strBody)
{
define(DEBUG, false);
define(DEBUG_FILE_PREFIX, "/tmp/findlinks_");
preg_match_all("/<[^>]+>(.*)<\/[^>]+>/U", $strBody, $strTag, PREG_PATTERN_ORDER);
$intOffset = 0;
$intIndex = 0;
$intTagPositions = array();
foreach($strTag[0] as $strFullTag) {
if(DEBUG == true) {
$fhDebug = fopen(DEBUG_FILE_PREFIX.time(), "a");
fwrite($fhDebug, $fulltag."\n");
fwrite($fhDebug, "Starting position: ".strpos($strBody, $strFullTag, $intOffset)."\n");
fwrite($fhDebug, "Ending position: ".(strpos($strBody, $strFullTag, $intOffset) + strlen($strFullTag))."\n");
fwrite($fhDebug, "Length: ".strlen($strFullTag)."\n\n");
fclose($fhDebug);
}
$intTagPositions[$intIndex] = array('start' => (strpos($strBody, $strFullTag, $intOffset)), 'end' => (strpos($strBody, $strFullTag, $intOffset) + strlen($strFullTag)));
$intOffset += strlen($strFullTag);
$intIndex++;
}
return $intTagPositions;
}
$strBody = 'I have lots of <a href="http://my.site.com">links</a> on this <a href="http://my.site.com">page</a> that I want to <a href="http://my.site.com">find</a> the positions.';
$strBody = strip_tags(html_entity_decode($strBody), '<a>');
$intTagPositions = getTagPositions($strBody);
print_r($intTagPositions);
/*****
Output:
Array (
[0] => Array (
[start] => 15
[end] => 53 )
[1] => Array (
[start] => 62
[end] => 99 )
[2] => Array (
[start] => 115
[end] => 152 )
)
*****/
?>
bruha
04-Mar-2008 12:13
04-Mar-2008 12:13
To count str_length in UTF-8 string i use
$count = preg_match_all("/[[:print:]\pL]/u", $str, $pockets);
where
[:print:] - printing characters, including space
\pL - UTF-8 Letter
/u - UTF-8 string
other unicode character properties on http://www.pcre.org/pcre.txt
dolbegraeb
28-Jan-2008 04:30
28-Jan-2008 04:30
please note, that the function of "mail at SPAMBUSTER at milianw dot de" can result in invalid xhtml in some cases. think i used it in the right way but my result is sth like this:
<img src="./img.jpg" alt="nice picture" />foo foo foo foo </img>
correct me if i'm wrong.
i'll see when there's time to fix that. -.-
mr davin
12-Jul-2007 02:57
12-Jul-2007 02:57
<?php
// Returns an array of strings where the start and end are found
function findinside($start, $end, $string) {
preg_match_all('/' . preg_quote($start, '/') . '([^\.)]+)'. preg_quote($end, '/').'/i', $string, $m);
return $m[1];
}
$start = "mary has";
$end = "lambs.";
$string = "mary has 6 lambs. phil has 13 lambs. mary stole phil's lambs. now mary has all the lambs.";
$out = findinside($start, $end, $string);
print_r ($out);
/* Results in
(
[0] => 6
[1] => all the
)
*/
?>
phektus at gmail dot com
26-Jun-2007 11:22
26-Jun-2007 11:22
If you'd like to include DOUBLE QUOTES on a regular expression for use with preg_match_all, try ESCAPING THRICE, as in: \\\"
For example, the pattern:
'/<table>[\s\w\/<>=\\\"]*<\/table>/'
Should be able to match:
<table>
<row>
<col align="left" valign="top">a</col>
<col align="right" valign="bottom">b</col>
</row>
</table>
.. with all there is under those table tags.
I'm not really sure why this is so, but I tried just the double quote and one or even two escape characters and it won't work. In my frustration I added another one and then it's cool.
chuckie
06-Dec-2006 06:20
06-Dec-2006 06:20
This is a function to convert byte offsets into (UTF-8) character offsets (this is reagardless of whether you use /u modifier:
<?php
function mb_preg_match_all($ps_pattern, $ps_subject, &$pa_matches, $pn_flags = PREG_PATTERN_ORDER, $pn_offset = 0, $ps_encoding = NULL) {
// WARNING! - All this function does is to correct offsets, nothing else:
//
if (is_null($ps_encoding))
$ps_encoding = mb_internal_encoding();
$pn_offset = strlen(mb_substr($ps_subject, 0, $pn_offset, $ps_encoding));
$ret = preg_match_all($ps_pattern, $ps_subject, $pa_matches, $pn_flags, $pn_offset);
if ($ret && ($pn_flags & PREG_OFFSET_CAPTURE))
foreach($pa_matches as &$ha_match)
foreach($ha_match as &$ha_match)
$ha_match[1] = mb_strlen(substr($ps_subject, 0, $ha_match[1]), $ps_encoding);
//
// (code is independent of PREG_PATTER_ORDER / PREG_SET_ORDER)
return $ret;
}
?>
phpnet at sinful-music dot com
20-Feb-2006 12:53
20-Feb-2006 12:53
Here's some fleecy code to 1. validate RCF2822 conformity of address lists and 2. to extract the address specification (the part commonly known as 'email'). I wouldn't suggest using it for input form email checking, but it might be just what you want for other email applications. I know it can be optimized further, but that part I'll leave up to you nutcrackers. The total length of the resulting Regex is about 30000 bytes. That because it accepts comments. You can remove that by setting $cfws to $fws and it shrinks to about 6000 bytes. Conformity checking is absolutely and strictly referring to RFC2822. Have fun and email me if you have any enhancements!
<?php
function mime_extract_rfc2822_address($string)
{
//rfc2822 token setup
$crlf = "(?:\r\n)";
$wsp = "[\t ]";
$text = "[\\x01-\\x09\\x0B\\x0C\\x0E-\\x7F]";
$quoted_pair = "(?:\\\\$text)";
$fws = "(?:(?:$wsp*$crlf)?$wsp+)";
$ctext = "[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F" .
"!-'*-[\\]-\\x7F]";
$comment = "(\\((?:$fws?(?:$ctext|$quoted_pair|(?1)))*" .
"$fws?\\))";
$cfws = "(?:(?:$fws?$comment)*(?:(?:$fws?$comment)|$fws))";
//$cfws = $fws; //an alternative to comments
$atext = "[!#-'*+\\-\\/0-9=?A-Z\\^-~]";
$atom = "(?:$cfws?$atext+$cfws?)";
$dot_atom_text = "(?:$atext+(?:\\.$atext+)*)";
$dot_atom = "(?:$cfws?$dot_atom_text$cfws?)";
$qtext = "[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F!#-[\\]-\\x7F]";
$qcontent = "(?:$qtext|$quoted_pair)";
$quoted_string = "(?:$cfws?\"(?:$fws?$qcontent)*$fws?\"$cfws?)";
$dtext = "[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F!-Z\\^-\\x7F]";
$dcontent = "(?:$dtext|$quoted_pair)";
$domain_literal = "(?:$cfws?\\[(?:$fws?$dcontent)*$fws?]$cfws?)";
$domain = "(?:$dot_atom|$domain_literal)";
$local_part = "(?:$dot_atom|$quoted_string)";
$addr_spec = "($local_part@$domain)";
$display_name = "(?:(?:$atom|$quoted_string)+)";
$angle_addr = "(?:$cfws?<$addr_spec>$cfws?)";
$name_addr = "(?:$display_name?$angle_addr)";
$mailbox = "(?:$name_addr|$addr_spec)";
$mailbox_list = "(?:(?:(?:(?<=:)|,)$mailbox)+)";
$group = "(?:$display_name:(?:$mailbox_list|$cfws)?;$cfws?)";
$address = "(?:$mailbox|$group)";
$address_list = "(?:(?:^|,)$address)+";
//output length of string (just so you see how f**king long it is)
echo(strlen($address_list) . " ");
//apply expression
preg_match_all("/^$address_list$/", $string, $array, PREG_SET_ORDER);
return $array;
};
?>
mnc at u dot nu
02-Feb-2006 10:05
02-Feb-2006 10:05
PREG_OFFSET_CAPTURE always seems to provide byte offsets, rather than character position offsets, even when you are using the unicode /u modifier.