Linux wildcard characters

The study of wildcards is a bit of a sense of laying the groundwork for regular expressions ... Python has learned regular expressions before, so this blog is still very quick to learn.

Special Symbols

|#pipe character, or (regular)>#Output Redirection>>#Output Append redirection<#Input REDIRECT<<#Append input Redirection~#Current User home directory`` $()#results after the reference command is executed$#to have a. End (Regular)^#to have a. Start (Regular)*#match all characters, wildcard characters？#any one character, wildcard characters##注释&#let the program or script switch to background execution&&#and set up at the same time[]#represents a range (regular, wildcard character){}#produces a sequence (wildcard character).#hard links to the current directory..#hard links to parent directories

wildcard characters

He's the shell's built-in feature.
Wildcard characters, used DOS should be well understood, but also very common.
Wildcard, which refers to the string containing these characters "? ","*","[]",{}

Wildcard meaning ===> matching file name

symbols	function
*	Matches any string/text, including an empty string; * represents any character (0 or more) LS file *
?	Match any one character (not in parentheses)? represents any 1 characters ls file 0
[ABCD]	Match any one of the ABCD characters
[A-z]	Represents the range A to Z, which indicates the meaning of the range [] matches any one of the characters in brackets ls file 0
{..}	Represents a build sequence. Separated by commas, and cannot have spaces
Add
[!ABCD]	or [^ABCD] denotes non, which means that any one of the characters in the parentheses does not match

a wildcard explanation

? Any one character

[ABCD] means that any one of the characters in the bracket is set.

• {} build Sequence

• [] used to find files (match file names)

Use {} to back up

[^ABCD]!^ means no, take counter

[] differs from {}

• [] can only be used to find files
• {} used to find files, or create files, generate sequences

Special Symbols

Command 1| command 2  ## #管道符号, passing the ordinary text, string, from the previous command. |xargs   ## #管道符号, convert a string to a file name by Xargs this pipe-break command

Directory structure

.   # current directory (or "any one character" regular)  : # Top level directory of current directory

REDIRECT Symbol

>   # output Redirect, will empty the original content, and then append to the file content >>  # Append output Redirect, append to the last line of the file <   # input redirect tr xargs<<  #cat to append multiple lines of text to a file

Uncategorized Special Symbols # denotes annotations

Linux will ignore him, to the Ops people to see, explain the use of.

The value of a reference variable to a variable or a command prompt for a normal user

1. Shell
$ variable: Take the contents of the variable

2. awk
$ $ number to fetch column

3. Command prompt for ordinary users

"(ESC below) The result of an anti-quote command, equivalent to $ ()

; separate multiple commands without a logical relationship, just step-by-step

1. Shell

2. Sed

' 20p;50p;100p '2050100

CD-; Su-

• CD- # # # returns to the last working directory , returning to the previous location
• Su- # # # Switch User, reload environment variable

~ Current user's home directory, home

[[Email protected] ~]$ CD ~ will return the current user's home directory directly

\ Escape symbol or call mask alias

.    # (the regex represents any one character)\.   # a symbol that represents only one point

！ Represents a non-

Represents a mandatory
Vi/vim
VI forced Exit (: q! )

&& expressed and

Note:the && symbol executes the following command only if the command that precedes it executes successfully

single quotes, double quotes, unquoted differences

• Single quotes: What you see is what you gain.

• Double quotation marks: parsing special symbols, special symbols have the original special meaning

• No quotes: More special, wildcard characters supported

Reference Blog: http://www.cnblogs.com/chensiqiqi/p/6280351.html

Linux wildcard characters