php不破坏单词截取子字符串

php不破坏单词截取子字符串

1. /*
2. snippet(phrase,[max length],[phrase tail])
3. snippetgreedy(phrase,[max length before next space],[phrase tail])
5. */
7. function snippet($text,$length=64,$tail="...") {
8. $text = trim($text);
9. $txtl = strlen($text);
10. if($txtl > $length) {
11. for($i=1;$text[$length-$i]!=" ";$i++) {
12. if($i == $length) {
13. return substr($text,0,$length) . $tail;
14. }
15. }
16. $text = substr($text,0,$length-$i+1) . $tail;
17. }
18. return $text;
19. }
21. // It behaves greedy, gets length characters ore goes for more
23. function snippetgreedy($text,$length=64,$tail="...") {
24. $text = trim($text);
25. if(strlen($text) > $length) {
26. for($i=0;$text[$length+$i]!=" ";$i++) {
27. if(!$text[$length+$i]) {
28. return $text;
29. }
30. }
31. $text = substr($text,0,$length+$i) . $tail;
32. }
33. return $text;
34. }
36. // The same as the snippet but removing latest low punctuation chars,
37. // if they exist (dots and commas). It performs a later suffixal trim of spaces
39. function snippetwop($text,$length=64,$tail="...") {
40. $text = trim($text);
41. $txtl = strlen($text);
42. if($txtl > $length) {
43. for($i=1;$text[$length-$i]!=" ";$i++) {
44. if($i == $length) {
45. return substr($text,0,$length) . $tail;
46. }
47. }
48. for(;$text[$length-$i]=="," || $text[$length-$i]=="." || $text[$length-$i]==" ";$i++) {;}
49. $text = substr($text,0,$length-$i+1) . $tail;
50. }
51. return $text;
52. }
54. /*
55. echo(snippet("this is not too long to run on the column on the left, perhaps, or perhaps yes, no idea") . "
    ");
56. echo(snippetwop("this is not too long to run on the column on the left, perhaps, or perhaps yes, no idea") . "
    ");
57. echo(snippetgreedy("this is not too long to run on the column on the left, perhaps, or perhaps yes, no idea"));
58. */