capitalize [首字母大写] 
count_characters [计算字符数] 
cat [连接字符串] 
count_paragraphs [计算段落数]
count_sentences [计算句数]
count_words [计算词数]
date_format [时间格式]
default [默认]
escape [转码]
indent[缩进]
lower[小写 ]
nl2br[换行符替换成<br />]
regex_replace[正则替换]
replace[替换]
spacify[插空]
string_format[字符串格式化]
strip[去除(多余空格)]
strip_tags[去除html标签]
truncate[截取]
upper[大写]
wordwrap[行宽约束]