egrep options

first, the basic concept expression: A regular expression is a logical formula for string manipulation, which is a "rule string" that is used to express a filter logic for a string, using predefined specific characters and combinations of these specific characters. grep(Global search Regular expression (RE) and print out of the line): A text Search tool that searches the target file based on a user-specified text pattern, Displays the rows that can be matched to the pattern (as a te

1. grep 1. Purpose:The text search tool performs a row-by-row search on the target file based on the user-specified text pattern to display the row content that can be matched by the pattern. 2. Command Format:Grep [Option] 'patten 'files... 2.1 explanation of common options 2.1.1 single file search: -N: displays the row number of the matched row (n + other options are used below to show clea

I. Introduction Grep is used to display the part.) match the rows in string format. Family: grep egrep fgrp Ii. How to Use grep Usage: grep [options] PATTERN file .. Options: -I case-insensitive -- Color Matching highlighted -O: only show Matching Parts -N: displays the matched rows and rows. -V Inversion -E: use an extended regular expression. -A n: displays th

file name before each line output.Grammar:grep [Options] [Find mode] [file name 1, file name 2, ...]egrep [Options] [Find mode] [file name 1, file name 2, ...]fgrep [Options] [Find mode] [file name 1, file name 2, ...]The options for this command have the following meanings

Linux Command Text Search tool grep, Egrep, Fgrepgrep, the global search regular Expression_r (RE) and print out, is a powerful text search tool that uses regular expressions to search for text and print matching lines.The grep family includes grep, Egrep, and Fgrep:egrep are the extensions of grep; Fgrep finds one or more rows in a file that matches the given string or phrase, does not support regular expr

Egrep function description: the egrep command and the grep command have the-E flag, except for the difference in the error message and the use of the message and the function of the-s flag. Use the egrep command to search for one or more files. the prompt can be an extension rule expression symbol. the extension rule expression symbol includes the rule expression

Grep,egrep,fgrep:print lines matching a pattern1.grep:grep [options] PATTERN FILE ...Pattern is made up of meta characters and ordinary characters-I:--ignore-case, ignoring case-O:--only-matching, displays only the characters that are matched, and two is not the whole line-N:--line-number, outputs the line number of the matched row-V:--invert-match, showing all rows except matching rows-e:--extended-regexp,

grep or Egrep or awk filters two or more keywords | using grep to match "and" or "or" mode 2011-06-23 14:06 grep or Egrep or awk filters two or more keywords:Grep-e ' 123|abc ' filename/find the line containing 123 or ABC in the file (filename)Egrep ' 123|abc ' filename//With EGREP can also be achievedHow a

Linux basic command grep egrep fgrep usage and regular expression 1. grep, egrep, and fgrep commands this article mainly introduces the basic parameters and usage formats of grep egrep fgrep commands and regular expressions in linux, method. (Note: fg stands for an example in this article.) 1.1. basic definition: www.2cto.com grep (global search regular RE) and p

"/>-O: Displays only the content that is matched by the pattern; 650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M00/5D/13/wKiom1Ugp8jxWn1oAARJrryCwCw792.jpg "title=" 10.png "Width=" "height=" 414 "border=" 0 "hspace=" 0 "vspace=" 0 "style=" width:600px;height:414px; "alt=" Wkiom1ugp8jxwn1oaarjrrycwcw792.jpg "/>650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M02/5D/13/wKiom1Ugpg-gZxhTAACNCKovFVE177.jpg "style=" float: none; "title=" 8.png "alt=" Wkiom1ugpg-gzxhtaacnckovfve177.j

The Grep,egrep command in a Linux system is a powerful text search tool that uses regular expressions and extended regular expressions to search for text and print the rows that match. Search for a specific string "the" Note: N is the display line number # grep-n ' the ' regular_express.txt2. Use the- v option to reverse the search for a specific string "the"# grep-vn ' the ' regular_express.txt3. Match the string with the case "the", u

The origin of regular expressionsRegular expressions, written in English regular expression, are often abbreviated as regex, REGEXP, etc. in programming languages. It is a single string used to describe and match a series of strings conforming to a certain sentence.Regular expressions are often used to retrieve and replace text that conforms to a pattern (pattern).In the 1950 's, the Father of Unix, Ken Thompson, introduced the regular expression into the editor QED, then the editor Ed, which wa

match ABX ABBX ABBBX' \ (ab\) \{1,3\}x ' can match ABX ABABX ABABABXBack reference: In the pattern, if you use \ (\) to implement the grouping, in a text check, if \ (\) pattern matches to a certain content, this content can be referenced in the following pattern;\1, \2, \3The pattern is from left to right, referencing the first # opening parenthesis and matching the pattern between the closing parenthesis and its matching right;grep options:-V: Reve

In the Linux system, there are three commonly used tools for processing text, and grep is one of the Three Musketeers, commonly known as text processing.grep is a powerful text search tool whose full name is: Globally search a Regular Expression and Print. It works by searching and filtering the text based on the given "pattern" of the regular expression engine and printing the matching lines. Therefore, to understand the use of grep we can proceed from two aspects, the use of the 1:grep command

overall back reference.Example: pat1\ (pat2\) pat3\ (pat4\ (pat5\) pat6\)where \1 is (PAT2), \2 is (PAT4\PAT5) ... \ n = (pat2\) pat3\ (pat4\ (pat5\) pat6\)In addition, Egrep also supports a "|" As a group separator, which is different from grep.Example: In order to better understand the group and the back reference, we create a file test ourselves.#vi Test Enter the following to save the exit.650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M0

regular expression that the command uses to find the specified string within the file. Full search of regular expressions and printing of rows is a powerful text-search tool that can use regular expressions to search for text and print matching lines.GREP[-ACINV] [--color=auto] ' search string ' filename 'Options and Parameters:- o : Shows only what is matched to the pattern- v : Displays rows that cannot be matched to a pattern- e : Using an ext

line if it contains the word North. The/ 4. grep's options Option What it does -B Precedes each line by the block number on which it was found. This is sometimes useful in locating disk block numbers by context. -C Displays a count of Matching lines rather than displaying the lines that match. -H Does not display filenames. -I Ignores the case of letters in making comparisons (I. e

Regular expressions I wrote the blog for the first time. The basic use of regular expressions has just been learned recently. Organized, and later used to review the search. The basic description of regular expressions:Basically, a regular expression is a pattern used to describe a certain amount of text, and the shorthand for regular expressions is the Regex full name regular Express.The first regular expression is very important for Linux OPS engineers, which will accompany every operational e

called a word;\\> or \b: The ending anchor for the right side of the word pattern;\Second, Egrep an extended regular expression implementation is similar to the grep text filtering feature; Grep-eEgrep [OPTIONS] PATTERN [FILE ...]Options:-I,-O,-V,-Q,-A,-B,-C-G: Support for basic regular expressionsExtend the metacharacters of regular expressions:Character Matchi

Text Processing tool grep, regular expressions in the Linux learning process is prone to confusion and obstacles in the place, here to share some of the experience of this content. grep Global search REgular expression and Print out of the lineFunction: Text Search tool, according to the user specified ' mode (filter condition) ' to match the target text line by row, print the matching line;' Pattern ': the filter condition written by the metacharacters and text characters of the regular e