Linux lower meta-character, regular expression, extended regular expression application

Linux under wildcard characters commonly used to search for files Ls,find

Symbolic meaning

* represents any character of any length

? Represents any single character

[] represents any single character within the specified range

[-] such as [A-z] represents any single character within a-Z

[^] Any single character outside the specified range

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Linux down Meta character

# annotation symbols, often used in scripts

\ escape character, to revert the "metacharacters or wildcards" to a normal character,

| Pipeline, you can place the contents on the left side of the pipe to the right of the pipeline to handle

; Delimiter for multiple commands

~ User Home Directory

The leader of the $ variable used to take the value of the variable

& Operation Control, put the command in the background to run

! "Non" in logical operation

/directory symbols, path delimited symbols

>,>> Data flow redirection, output redirection

<,<< Data flow redirection, input redirection

' Single quotes, special characters or wildcards do not escape to represent the original character

"" double quotes, variable with displacement function

"Anti-quote, ESC key under the button, can make a command reference to $ ()

() Middle is the beginning and end of the child shell

{} In the middle is a combination of command blocks

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Regular expressions under Linux are commonly used to match characters, grep

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[: Alnum:] On behalf of the English uppercase and lowercase characters and digital 0-9,a-z,a-z, use need to add [], such as [[: Alnum:]], the following is the same

[: Alpha:] represents English uppercase and lowercase characters

[: Blank:] represents the space Bar and TAB key

[:d Igit:] Represents a number

[: Lower:] represents lowercase characters in English

[: Upper:] represents the uppercase characters in English

[:p UNCT:] represents punctuation

[: Space:] represents a blank character

Basic Regular Expression characters

^string represents a string beginning with string

string$ represents a string ending in string

. Represents any single character

\ represents the escape character

* indicates that the preceding character appears 0 or any time

\b,\< Anchor Word Head

\b,\> Anchor Ending

[List] represents a single character in the [list] range

[-] represents a single character in the [-] range

[^list] Represents a single character outside the range of [list]

\{n,m\} represents at least n occurrences of the preceding character at most times M

Extended Regular expression character egrep, grep-e

+ represents one or more occurrences of the preceding character

? Represents the preceding character 0 or 1 times

| Representative or

() represents a group of strings

() + indicates any number of occurrences of the group string

This article is from the "Happy is good" blog, please be sure to keep this source http://wdllife.blog.51cto.com/6615958/1601933

Linux lower meta-character, regular expression, extended regular expression application