linux grep regular expression

From: http://hi.baidu.com/nearlove/blog/item/11db98b6b5b8aff831add1e5.html The first thing to remember is that regular expressions and wildcards have different meanings!A regular expression is only a representation. As long as the tool supports this representation, the tool can process the string of a regular

, does not match A;[Email protected] ~]# grep-e "Go+d" test1My god,i am not oldbey,but OldboyGoodGoood(2)? : Match the previous 0 or 1 times---ab? Indicates matching A or AB, does not match ABB;[Email protected] ~]# grep-e "Go?d" test1My god,i am not oldbey,but OldboyGd(3) | : Match any of the---ab|cd to match ab or CD;[Email protected] ~]# grep-e "God|good" test

$ match end of line grep "^m" Test_rule.txt Match lines that start with capital M grep "n$" Test_rule.txt Matches a line ending in lowercase n Grep-n "^$" Test_rule.txt Match Blank Line 4 [] matches any one of the characters specified in parentheses, matching only one character grep "S[ao]id" Test_rule.t

A regular expression is only a representation. As long as the tool supports this representation, the tool can process the string of a regular expression. Vim, grep, awk, and sed both support regular expressions, and they seem powe

The first thing to remember is that regular expressions are not the same as wildcards, and they represent different meanings!A regular expression is just a notation, and the tool can handle a string of regular expressions as long as the tool supports that notation. Vim, grep

' Connect the display results of PS with the pipe character and grep, displaying all lines with a space at the beginning of the line and containing multi 2) EgrepEgrep is the extension of grep and can be used with other wildcard characters+: More than 1 characters？ : There are 0 or 1 charactersA|b: Matches the character of A or b(): Character Group3) FgrepSimilar to

Linux regular expression 1. some special symbols 2. first-line control character ^, last-line control character $ [html] find the first rule containing the: [root @ www ~] When grep-namp;%39%%theamp;%39%regular_express.txt start with a lowercase letter: # grep-n amp; #39; ^

"Hequan\Hequan"Hequan Hequan# echo-e "Hequan\nhequan"HequanHequan# lang=en# date ' +%y-%m-%d '16-03-30# date ' +%y-%m-%d '2016-03-30# date +%w3# date +%u3Cut# echo ' Date +%f\%T '2016-03-30 17:06:52Tar# tar zcvf/tmp/qwe2.tar.gz./etc/# tar zcvf/tmp/qwe-$ (date +%f-%t). tar.gz./etc/# tar zcvf/tmp/qwe-$ (date +%w). tar.gz./etc/# find/log-type F-name "*.log"-mtime +7 |xargs rm-f#/usr/sbin/ntpdate Time.ntvs.gov# echo $PATH/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin# cal# w

: print only the letter grep "\w" H.txt --A B c d e F g h i \w : print non-letter \b : match the delimiter of the word grep "\bhello\b" h.txt\d : Represents a numberCommon Command DisplayLinux grep/egrep Command DetailedLinux sed command detailedLinux awk Command DetailsExtended Regular ExpressionExtended

1. What is a regular expressionWhen doing a word processing or writing a program, use the Find, replaceand other functions, use regular expressions to achieve goals quickly and easily。 In simple terms, regular expressions help with some special symbols, so that users can easily and quickly complete the search, deletion, replacement and other processing programs.