Linux Basic Test--11 problem

000. Create a directory/data

1 mkdir/data

001. Create a file under/data oldboy.txt

1 touch/data/oldboy.txt

002. Add content for Oldboy.txt to "I am studying Linux."

1 vi/data/oldboy.txt #点按i键进入编辑模式 2 I am studying Linux.  #点按ESC键退出编辑模式 3~                                                                                                                                                     4~                                                                                                                                                     5~                                                                                                                                                 
  : Wq

003. Copy the Oldboy.txt file to/tmp

Cp/data/oldboy.txt/tmp

004. Move the/data directory to the/root

Cp/data/oldboy.txt/tmp

005. Enter the data directory under the/root directory to delete the Oldboy.txt file

Cd/root/data
Find-type f-name ' oldboy.txt ' |xargs rm

006, answer the question, exit to the previous level directory, delete the data directory

Cd.. \rm-r  /root/data

007, the known file Test.txt content is:　

1 Test 2 Liyao 3 Oldboy

Please give a command that does not include the Oldboy string when outputting the contents of the Test.txt file

Create a test environment

1 [email protected]/]# Touch/data/test.txt 2 [email protected]/]# Cd/data 3 [ Email protected] data]# vi test.txt               #创建环境 4[[email protected] data]# cat Test.txt #查看测试 File 5test6Liyao7 Oldboy

1. Head command

1 [email protected] data]# head-2/data/test.txt 2 Test 3 Liyao

2. grep command

1 [email protected] data]# grep-v ' Oldboy '/data/test.txt 2 Test 3 Liyao

3. SED command

1 [[email protected] data]# sed '/oldboy/d '/data/test.txt 2 Test 3 Liyao

008. Use a command to complete the creation of the directory/oldboy/test, that is to create the/oldboy directory and/oldboy/test directory

1. Clumsy wording

Mkdir/oldboy/oldboy/test

2. Elegant notation

Mkdir-p/oldboy/test

009, known AS/tmp already exists Test.txt file, how to execute the command to the/mnt/test.txt copy to/tmp cover off/tmp/test.txt, and let the system does not prompt whether to overwrite (root authority).

　　Use cp-f directly, fail.

1, first think even use cp-f will also prompt whether to overwrite, and then think of the Linux alias mechanism:

12alias cp= ' cp-i '3alias l.= ' ls-d. *--color=auto '4  Alias ll= ' ls-l--color=auto '5alias ls= ' ls--color=auto '6alias mv= ' Mv-i '  7alias rm= ' echo * use more secure command '8 alias Which= ' Alias | /usr/bin/which--tty-only--read-alias--show-dot--show-tilde '

You can see that Linux executes the CP command when the default parameter is-I, modifying the default parameter to-F (dangerous, only for the purpose of the problem):

1 [email protected]/]# Touch/mnt/test.txt 2 [email protected]/]# cp/mnt/test.txt/tmp 3

You can see that there is no prompt to overwrite directly.

2. Use \

1 [email protected]/]# \cp/mnt/test.txt/tmp 2

010. View only the contents of lines 20th through 30th in the Ett.txt file (total 100 lines)

To create a test environment:

  1[[email protected]/]# seq >ett.txt  2[[email protected]/]# cat Ett.txt    31  42  53  6 4   75          #太长省略

1. Use head, tail command

1 [email protected]/]# Head-30/ett.txt | tail-11 2  - 3  + 4  A 5  at 6  - 7  - 8  - 9  - Ten  -  One  in  30

2. Using the SED command

1 [email protected]/]# sed-n ' 20,30p ' ett.txt 2  - 3  + 4  A 5  at 6  - 7  - 8  - 9  - Ten  -  One  in  30

#说明: The above code reference study "old boy education 36 preview Video"

#https://linux.cn/

#https://linux.cn/article-2713-1.html

Linux Basic Test--11 problem