正则表达式

Table of Contents


基本概念

. 匹配任意字符  
[ ] 匹配指定字符 [abcdXYZ0123456789] 等同 [a-dX-Z0-9]
[^ ] 排除指定字符 [^abc] 等同 [^a-c], 将匹配任意字符但除了 a, b, c
^ 行首  
$ 行尾  
| 选择操作 gray|grey 将会匹配 graygrey
( ) 分组(定义一个子表达式) gr(a|e)y 将会匹配 graygrey

量化

{n} times == n  
{min,} times >= min  
{min, max} times >= min && times <= max  
? 等同 {0, 1} colou?r 将会匹配 colorcolour
* 等同 {0,} ab*c 将会匹配 ac, abc, abbc, abbbc
+ 等同 {1,} ab+c 将会匹配 abc, abbc, abbbc… 但不会匹配 ac

字符集

POSIX Non-standard Perl/Tcl Vim ASCII (不要忽视'[]'里面的空格;)
[:alnum:]       [A-Za-z0-9]
  [:word:] \w \w [A-Za-z0-9_]
    \W \W [^A-Za-z0-9_]
[:alpha:]     \a [A-Za-z]
[:blank:]     \s [ \t]
    \b \< \> (?<=\W)(?=\w)|(?<=\w)(?=\W)
[:cntrl:]       [\x00-\x1F\x7F]
[:digit:]   \d \d [0-9]
    \D \D [^0-9]
[:graph:]       [\x21-\x7E]
[:lower:]     \l [a-z]
[:print:]     \p [\x20-\x7E]
[:punct:]       [][!"#$%&'()*+,./:;<=>?@\^_`{|}~-]
[:space:]   \s \_s [ \t\r\n\v\f]
    \S \S [^ \t\r\n\v\f]
[:upper:]     \u [A-Z]
[:xdigit:]     \x [A-Fa-f0-9]

参考

Author: Saul Lawliet

Created: 2019-03-21 Thu 16:45

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