Rhcsa learning practice

1. Use whereis lookup locate command

         Use which lookup whereis command

         Use locate lookup rm command

[[email protected] ~]# locate -c rm 
5228
[[email protected] ~]# whereis locate
locate: /usr/bin/locate /usr/share/man/man1/locate.1.gz
[[email protected] ~]# which whereis
/usr/bin/whereis

2.find Command to use ： Use find Command to find all ordinary files in the current path Use find Command to find... In the current path file1.txt,file2.txt,file3.txt Use find The command to find the file owner is root The ordinary documents of Use find The command search modification time is 1 Ordinary documents within days

[[email protected] ~]# find -type f  #  All text files 
[[email protected] ~]# find -type l	 #  All linked files 
[[email protected] ~]# find find_test1 find_test2 find_test3
find_test1
find_test2
find_test3

[email protected] ~]# find  -user root | find -type l #  Find the user as root Common files under 
[[email protected] ~]# find -mtime -1 |find -type l	  #  Documents modified within one day 

3.cut Command to use ： Given the file cut_data.txt And the content is ： No Name Score 1 zhang 20 2 li 80 3 wang 90 4 sun 60 Use the default delimiter to cut the contents of the file , And output the first field after cutting Cut file content , And output the first field and the third field after cutting Cut by byte ： Output the first byte to the second byte of the cut 10 Bytes of content Cut by character ： Output the first character and the second character after cutting 5 The content of a character Cut according to the specified delimiter ： The contents are as follows , Output the contents of the first field and the third field No|Name|Score 1|zhang|20 2|li|80 3|wang|90 4|sun|60

[[email protected] ~]# cut -s -f1 cut_data.txt
[[email protected] ~]# cut -s -f1,3 cut_data.txt 
[[email protected] ~]# cut -b 1-10 cut_data.txt
[[email protected] ~]# cut -c 1-5 cut_data.txt
[[email protected] ~]# cut -d"|" -f 1,3 cut_data.txt

4.uniq Command to use ： New file uniq_data.txt, The content of the document is Welcome to Linux Windows Windows Mac Mac Linux Use uniq The command outputs the result after de duplication Use uniqmingl Output only duplicate lines Use uniq The command outputs non repeating lines Use uniq The command counts the number of repetitions

[[email protected] ~]# uniq uniq_data.txt	
[[email protected] ~]# uniq -d uniq_data.txt 
[[email protected] ~]# uniq -u uniq_data.txt
[[email protected] ~]# uniq -c -d  uniq_data.txt

 5.sort command ： Given the file num.txt, args.txt The contents of the document :num.txt 1 3 5 2 4 The contents of the document :args.txt test args1 args2 args4 args4 args3

  Yes num.txt Sort , And output the results to sorted_num.txt in

 

[email protected] ~]# sort -n  num.txt > sorted_num.txt

Yes args.txt Sort , And output the results to sorted_args.txt in

 

[[email protected] ~]# sort -n args.txt > sorted_merge.txt

Yes num.txt and args.txt Sort , And output the results to sorted_merge.txt in

[[email protected] ~]# sort -n args.txt num.txt  > sorted_merge.txt

Yes args.txt After sorting, de re output

[[email protected] ~]# sort -n -u args.txt

Merge sorted_args.txt and sorted_num.txt And output

[[email protected] ~]# sort args.txt num.txt 

Given the file info_txt： Press the second column as key Sort ​ No Name Score ​ 1 zhang 20 ​ 2 li 80 ​ 3 wang 90 ​ 4 sun 60

[[email protected] ~]# sort -n  -k 2  info.txt

6. take 26 After a lowercase letter 13 Replace the first letter with a capital letter

  take hello 123 world 456 Replace the numbers in with empty characters （ Prompt to use wildcards ）

take hello 123 world 456 Replace letters and spaces in , Just keep the numbers ( Prompt to use wildcards )

 7.wc Command to use ： Given the file ：word_count.txt, It's filled with 10 Row content Count by byte Count by word Count by

[[email protected] ~]# wc -l word_count.txt  #  Count by 
10 word_count.txt
[[email protected] ~]# wc -w word_count.txt #  Count by word 
11 word_count.txt
[[email protected] ~]# wc -c word_count.txt #  Count by byte