[Boiled Water]-shell-xargs knowledge summary-Knowledge point

pipelines are implemented " The previous standard output is used as the following standard input "

Xargs is to achieve " to use standard input as a parameter to a command "

Contrast:

Ind/sbin-perm +700 |ls-l

Find/sbin-perm +700 |xargs ls-l

Parameters and Usage:

-0: When the Sdtin contains special characters, it is treated as a general character, such as "space", etc.

# echo "//" |xargs-0 echo > aaa# echo "//" |xargs echo > bbb# cat-a aaa//$$# cat-a bbb//$

-A file is read from files as Sdtin

$ cat>1.txt<<eof AAA BBB CCC Ddda beof$ xargs-a 1.txt echoaaa BBB CCC DDD a B

-e flag, note that sometimes-e,flag must be a space-delimited flag that stops when Xargs analyzes the flag that contains flag.

#使用小e参数, there will be waiting input, it is recommended to use large E

$ Xargs-e ' ddd '-a 1.txt echoaaa bbb ccc$ cat 1.txt |xargs-e ' DDD ' echoaaa BBB CCC

-N num followed by the number of times, indicating the number of times the command was executed at the time of execution, argument by default.

$ cat 1.txt |xargs-n 2 echoaaa bbbccc Ddda b

#如果将所有filed排成一列

$ cat 1.txt |xargs-n 1

-R No-run-if-empty If there are no parameters to process to Xargsxargs by default is with empty parameters run once, if you want no parameters, stop Xargs, direct exit, use the-r option, it can prevent xargs command with empty parameters run error.

$ echo "" |xargs-t mvmv mv:missing file operandtry ' mv--help ' for more information.$ echo "" |xargs-t-R MV #直接退 Out

-S NUM xargs the maximum number of command-line characters (with spaces) behind that command

$ cat 1.txt.bak |xargs-s 9 Echoaaabbbcccddda b$ cat 1.txt.bak |xargs-s 4 Echoxargs:can not fit single argument within argument list size limit #length (echo) =4$ cat 1.txt.bak |xargs-s 8 echoxargs:argument line too long #length ( echo) =4,length (AAA) =3,length (NULL) =1,total_length=8

-I or-I, which depends on Linux support, will be the xargs of each name, usually a line assigned to {}, you can use {} instead.

$ ls1.txt 2.txt 3.txt log.xml$ ls *.txt |xargs-t-i mv {} {}.bakmv 1.txt 1.txt.bak mv 2.txt 2.txt.bak MV 3.txt 3.txt.b AK $ ls1.txt.bak 2.txt.bak 3.txt.bak log.xml

Note that-I must specify the replacement character-i specifies the substitution character-optional

Find. | Xargs-i {} CP {} $D _path

And

Find. | Xargs-i CP {} $D _path

Note: In Cshell and Tcshell, you need to enclose {} in single quotation marks, double quotes, or backslashes, otherwise you do not know. Bash can be used without.

Find/shell-maxdepth 2-name A-print | Xargs-t-I sed-i ' 1 i\111 ' {} '

The-p operation is interactive, with each execution comand interactively prompting the user to select, asking the user every time a argument is executed

$ cat 1.txt |xargs-p Echoecho AAA BBB CCC ddd a B?... yaaa BBB CCC ddd a b$ cat 1.txt |xargs-p echoecho AAA BBB CCC DDD A b?... n

-T means that the command is printed before execution.

$ cat 1.txt |xargs-t Echoecho AAA BBB CCC DDD a B AAA BBB CCC DDD A B

-L reads NUM lines once from standard input to command commands, like the-L and-l functions

$ cat 1.txt.bak AAA BBB CCC Ddda bcccdsds$ cat 1.txt.bak |xargs-l 4 echoaaa BBB CCC DDD a B CCC dsds$ cat 1.txt.bak |xar Gs-l 1 echoaaa BBB CCC Ddda BCCCDSDS

The-D delimter delimiter, the default Xargs delimiter is carriage return, the delimiter for argument is a space, and the Xargs delimiter is modified here

$ cat 1.txt.bak[email protected] bbb [email protected] Ddda b$ cat 1.txt.bak|xargs-d ' @ ' echoaaa BBB CCC Ddda b

- x Exit meaning that if there is any Command row greater than - s Size flag Specifies the number of bytes to stop running Xargs command, -l-i-N Open By default - x parameters, mainly with the - S Use

- P Modify the maximum number of processes, default is 1 , for 0 Time for As Manyas it can .

Instance Usage :

find . -perm -7-print | xargs chmod o-w          #在当前目录下查找所有用户具有读, write and Execute permissions files, and reclaim the appropriate write permissions find . -type f-print | xargs  file                      #查找系统中的每一个普通文件, and then use the Xargs command to test what kind of file they belong to Find ~ -name ' *.log '  -print0 |  xargs -i -0 rm -f {}                 #rm删除文件太多 to avoid/bin/rm argument list too long errors find  / -name *.jpg-type f -print | xargs tar -cvzf images.tar.gz  #查找所有的jpg   file, and compress it ls *.jpg | xargs-n1 -i cp {} /external-hard-drive/ directory           #拷贝所有的图片文件到一个外部的硬盘驱动find  / - Perm +7000 | xargs ls -l                     #  the previous content as the parameter of the following command seq 1 10 |xargs  -i date  -d  "{} days " +%y-%m-%d   #  lists 10 day dates Seq 1 10 |xargs   -i touch  "{}.txt"                   #一次生成10个空文件cat  a.txt | xargs            #  Career cat a.txt | xargs -n1        #  Row to column find .| Xargs grep -ri "192.168.1.112"        #找出目下下所有文件包含192.168.1.112 characters   ssh -n  $ip   ' find  ' $path '  /data /opt -typef  -name  "*.sh"  -or -name "*.py"  -or -name  "*.pl"  |xargs tar zcvpf /tmp/data_Backup.tar.gz ' #远程打包 

Reference:

http://czmmiao.iteye.com/blog/1949225

http://blog.csdn.net/yhcharles/article/details/44875865

http://blog.csdn.net/zhangfn2011/article/details/6776925/

http://blog.csdn.net/yongan1006/article/details/8134581

http://czmmiao.iteye.com/blog/1949225

Http://www.cnblogs.com/perfy/archive/2012/07/24/2606101.html

[Boiled Water]-shell-xargs knowledge summary-Knowledge point