Implementation code for php to automatically add keyword links to articles

/**
* Add article keywords and internal links
* by bbs.it-home.org
*/
$link = array(
'Baidu,http://www.baidu.com/',
'dedecms,http://bbs. it-home.org/',
);
$str = 'Search dedecms in Baidu';
$out = keylink ($str, $link, 1);
//$str original character $link, replace link Array, 3 replacement times
echo $out;
function _sortDesc($a, $b) {
return (strlen ( $a [0] ) < strlen ( $b [0] )) ? 1 : – 1;
 }
function keylink($str, $link, $count = 1) {
$linkDefs = $link;
$linkMap = array ();
foreach ( $linkDefs as $row ) {
$linkMap [] = explode ( ',', $row );
}
foreach ( $linkMap as $row ) {
$str = preg_replace ( '/(s*)(' . $row [0] . ')(s*}
usort ( $linkMap, '_sortDesc' );
$tmpKwds = array ();
foreach ( $linkMap as $i => $ row )
{
list ( $kwd, $url ) = $row;
for($j = $i + 1; $j < count ( $linkMap ); $j ++)
{
$subKwd = $ linkMap [$j] [0];
//If it contains other keywords, temporarily replace it with other strings
if (strpos ( $kwd, $subKwd ) !== false)
{
$tmpKwd = '{' . md5 ( $subKwd ) . '}';
$kwd = str_replace ( $subKwd, $tmpKwd, $kwd );
$tmpKwds [$tmpKwd] = $subKwd;
}
}
//Replace text with link
 $str = preg_replace ( '/(' . $row [0] . ')/sui', '' . $kwd . '', $str, $count );
}
//Replace the string that replaces the subkeyword back
foreach ( $tmpKwds as $tmp => $kwd ) {
$str = str_replace ( $tmp, $kwd, $str );
}
return $str;
}
?>