php自动给文章加关键词链接的实现代码

2. /**
3. * 添加文章关键词，内链
4. * by bbs.it-home.org
5. */
6. $link = array(
7. ‘百度,http://www.baidu.com/’,
8. ‘dedecms,http://bbs.it-home.org/’,
9. );
10. $str = ‘在百度中搜索dedecms’;
11. $out = keylink ( $str, $link, 1 );
12. //$str 原始字符 $link，替换链接数组, 3替换次数
13. echo $out;
14. function _sortDesc($a, $b) {
15. return (strlen ( $a [0] ) }
16. function keylink($str, $link, $count = 1) {
17. $linkDefs = $link;
18. $linkMap = array ();
19. foreach ( $linkDefs as $row ) {
20. $linkMap [] = explode ( ‘,’, $row );
21. }
22. foreach ( $linkMap as $row ) {
23. $str = preg_replace ( ‘/(s*)(‘ . $row [0] . ‘)(s*)/sui’, ‘${2}’, $str );
24. }
25. usort ( $linkMap, ‘_sortDesc’ );
26. $tmpKwds = array ();
27. foreach ( $linkMap as $i => $row )
28. {
29. list ( $kwd, $url ) = $row;
30. for($j = $i + 1; $j {
31. $subKwd = $linkMap [$j] [0];
32. //如果包含其他关键字，暂时替换成其他字符串
33. if (strpos ( $kwd, $subKwd ) !== false)
34. {
35. $tmpKwd = ‘{‘ . md5 ( $subKwd ) . ‘}’;
36. $kwd = str_replace ( $subKwd, $tmpKwd, $kwd );
37. $tmpKwds [$tmpKwd] = $subKwd;
38. }
39. }
40. //把文字替换成链接
41. $str = preg_replace ( ‘/(‘ . $row [0] . ‘)/sui’, ‘’ . $kwd . ‘’, $str, $count );
42. }
43. //把代替子关键字的字符串替换回来
44. foreach ( $tmpKwds as $tmp => $kwd ) {
45. $str = str_replace ( $tmp, $kwd, $str );
46. }
47. return $str;
48. }
49. ?>

复制代码