egrep syntax

Grep nobody/etc/passwd display rows with nobody characters in/etc/passwd, case sensitive Grep-I nobody/etc/passwd real-world/etc/passwd rows with nobody characters, case insensitive Grep-V nobody/etc/passwd rows that do not contain the nobody Grep-N nobody/etc/passwd: displays the row containing the nobody and the row number. Egrep is the extended grep Egrep '2 | 5' test: List rows containing 2 or 5

Grep, egrep, and fgrep for basic regular expressions and text processing tools Grep (Global Search Regular Expression and print out the line global search Regular Expression and print out the rows) is a powerful text search tool, the commands of egrep and fgrep are only slightly different from those of grep. Linux uses the GNU version of grep, which is very powerful and can be passed through-G,-E, -F comman

1.grep and Egrep Introduction grep full name is the global Regular Expressiongrep is a powerful text search tool for searching and filtering specific characters. Support regular expressions, can help us to filter, filter the common work. and can be used with a variety of commands through the pipeline, flexible and convenient. Its use rights are for all users. 1.1 regular Expressions (RegularExp ression REGEX )Before learning the grep

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., upper -- and lowercase are considered iden

Egrep and extended regular expressions, conditional expressions, and arithmetic operationsLinux05Linux05_01? Use and extend regular expressions in egrepREGEXP: REGular EXPression. It may not represent its own meaning, but it is used for special meanings such as anchoring.Pattern: filtering conditions used to filter text by combining metacharacters and characters of Regular ExpressionsRegular Expression:Basic REGEXP: BasicExtended REGEXP: ExtendedBasic

/meminfo For example, if the default shell is not bash # Grep-V "bash $"/etc/passwd | cut-D:-F1 For example, retrieve the user whose default shell is Bash and whose ID is the largest # Grep "bash $"/etc/passwd | sort-n-t:-K3 | tail-1 | cut-D:-F1 For example, the/etc/rc. d/rc. sysinit file starts with #, followed by at least one blank character, and then contains at least one non-blank line. # Grep "^ # [[: Space:] \ {1, \} [^ [: Space:] \ {1, \}"/etc/rc. d/RC. sysinit For example, find one or tw

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

Mode: patternRegular:grep: Basic RegularExtended grep: Extending the regularBasic Regular:. : Any single character[]: Within the specified range[^]: outside the specified rangeNumber of Matches*: Characters appear any time?: Characters appear 0 or 1 times\{m,n\}: Characters appear at least m times, at most n times\{1,\}: Characters appear at least 1 times. *: Matches any character of any lengthAnchoring:^: Anchoring the beginning of the line$: Anchor Line End\\> or \b: Anchor word endings\(\)\ (

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 Matching:.: Any single character[]: Any single character within the specified range[^]: Any sing