字符 | 描述 | 例子 |
. (点) | 任何单个字符，除了换行( ) | c.t 匹配 "cat", "cut" 或 "cot."。 '任意字符加im'： [root@test: /tmp]# egrep '.im' a.txt who simply need a little refresher from time to time. |
* (星号) | 重复前一个表达式0或多次 | 12*3 匹配 "13", "123", "1223", "12223"。 与 . 合用代表任何字符。 m.*easier 匹配 "maketecheasier"。 'x加任意个0加1:' [root@test: /tmp]# egrep 'x0*1:' a.txt 0x1: 0x00001: 0x0000001: '任何包含f加任意字符加l' [root@test: /tmp]# egrep 'f.*l' a.txt how useful regular expressions are. will be useful for people |
+ (加号) | 重复前一个表达式1或多次 | 12+3 匹配 "123","1223","12223" 'x加至少一个0加1:' （比较上一个用*的） [root@test: /tmp]# egrep 'x0+1:' a.txt 0x00001: 0x0000001: |
? (问号) | 前一个字符可有可无 | ma?ke 匹配 "make", "mke" '有n或无n加ee' [root@test: /tmp]# egrep 'n?ee' a.txt This Regular Expressions cheatsheet who simply need a little refresher |
^ (尖号) | 匹配字符串的开头 | ^he 匹配以he开头的 "hello", "hell", "help", "he is a boy" '以空格开头的行' [root@test: /tmp]# egrep '^ ' a.txt how useful regular expressions are. are everywhere in Linux for searching through text right down to the character. will be useful for people who simply need a little refresher from time to time. |
$ (美刀) | 匹配字符串的结尾 | ed$ 匹配以ed结尾的 "acted", bed", "greed" '字母e结尾的行' [root@test: /tmp]# egrep 'e$' a.txt you’ll appreciate from time |
(...) (小括号) | 匹配字符组合 | (ak) 匹配 "make", "take" '包含 it 的' [root@test: /tmp]# egrep '(it)' a.txt If you work with text, who simply need a little refresher |
{n} (大括号，n是大于0的整数) | 重复前一个字符n次，n>0 | 12{3}5 匹配 "12225" 'x加4个0加1' [root@test: /tmp]# egrep 'x0{4}1' a.txt 0x00001: |
[...] (中括号) | 匹配里面的任意一个字符 | [abc] 匹配字符串"abc"中的"a","b" 或 "c" '所有包含v或b的' [root@test: /tmp]# egrep '[vb]' a.txt are everywhere in Linux will be useful |
[^...] | 匹配任意字符，除了里面定义的 | a[^b]c 匹配 "aec", "acc", "adc", 但不匹配 "abc" 'f前面不能是空格或e' [root@test: /tmp]# egrep '[^ e]f' a.txt If you work with text, |
| (管道符) | 匹配管道符分隔的任一字符串 | col(o|ou)r 匹配 "color", "colour"
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- (连字符) | 指定某个范围内的字符一般是[a-z],[A-Z],[1-9],[a-zA-Z1-9] | a[a-z]c 匹配 "abc", "acc", "adc" |
(反斜线) | 转义符，将特殊符合转义为符号本身 | a*c 匹配 "a*c". |
, , | 代表 换行，回车，制表符 |
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... | 匹配整个单词 | Tech 匹配 the word "Tech" in "Make Tech Easier". 找到单词time [root@test: /tmp]# egrep 'time' a.txt from time to time. |