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.
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