修改方式:

在你的模版页面，需要截取限制标题的长度地方 

例如{#$art.art_title#} 把这个标签里面添加{#$art.art_title|truncate:限制的字数:""#}

就可以了 

关于truncate函数的使用方法参考如下：

truncate 
截取

This truncates a variable to a character length, default is 80. 
As an optional second parameter, you can specify a string of text to display at the end if the variable was truncated. The characters in the string are included with the original truncation length. 
By default, truncate will attempt to cut off at a word boundary. 
If you want to cut off at the exact character length, pass the optional third parameter of true.

从字符串开始处截取某长度的字符.默认是80个.
你也可以指定第二个参数作为追加在截取字符串后面的文本字串.该追加字串被计算在截取长度中。
默认情况下,smarty会截取到一个词的末尾。
如果你想要精确的截取多少个字符,把第三个参数改为"true"

index.php:

$smarty = new Smarty;
$smarty->assign('articleTitle', 'Two Sisters Reunite after Eighteen Years at Checkout Counter.');
$smarty->display('index.tpl');

index.tpl:

{$articleTitle}
{$articleTitle|truncate}
{$articleTitle|truncate:30}
{$articleTitle|truncate:30:""}
{$articleTitle|truncate:30:"---"}
{$articleTitle|truncate:30:"":true}
{$articleTitle|truncate:30:"...":true}

OUTPUT:

Two Sisters Reunite after Eighteen Years at Checkout Counter.
Two Sisters Reunite after Eighteen Years at Checkout Counter.
Two Sisters Reunite after...
Two Sisters Reunite after
Two Sisters Reunite after---
Two Sisters Reunite after Eigh
Two Sisters Reunite after E...