shell入门8-grep的正则表达式使用

这里就介绍得比较全了，有基本的，扩展的，POSIX的，GNU的，确实这本书不错。

一，基本的正则表达式

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二，扩展正则表达式

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三，POSIX规范的正则表达式

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四，GNU规范的正则表达式

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五，实践测试

1008  cp /etc/passwd /tmp/
 1009  grep "root" /tmp/passwd 
 1010  grep ":..0:" /tmp/passwd 
 1011  grep "00*" /tmp/passwd 
 1012  grep "o[os]t" /tmp/password
 1013  grep "o[os]t" /tmp/passwd 
 1014  grep "[0-9]" /tmp/passwd 
 1015  grep "[f-q]" /tmp/passwd 
 1016  grep "^root" /tmp/passwd 
 1017  grep "bash$" /tmp/passwd 
 1018  grep "sbin/[^n]" /tmp/passwd 
 1019  grep "0\{1,2\}" /tmp/passwd 
 1020  grep "\(root\).*\1" /tmp/passwd 
 1021  grep "^$" /tmp/passwd 
 1022  grep -v "^$" /tmp/passwd 
 1023  grep "0{1,2}" /tmp/passwd 
 1024  egrep "0{1,2}" /tmp/passwd 
 1025  grep -E "0{1,2}" /tmp/passwd 
 1026  grep "0+" /tmp/passwd 
 1027  egrep "0+" /tmp/passwd 
 1028  egrep "(root|admin)" /tmp/passwd 
 1029  grep "[[:digit:]]" /tmp/passwd 
 1030  grep "[[:alpha:]]" /tmp/passwd 
 1031  grep "[[:punct:]]" /tmp/passwd 
 1032  grep "[[:space:]]" /tmp/passwd 
 1033  grep "i\b" /tmp/passwd 
 1034  grep "\W" /tmp/passwd 
 1035  grep "\w" /tmp/passwd 
 1036  grep -P --color "\d" /etc/passwd
 1037  grep -P --color "\D" /etc/passwd

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