Rhcsa day 4 operation

1、 Find command usage

Use whereis lookup locate command

[root@localhost ~]# whereis locate
locate: /usr/bin/locate /usr/share/man/man1/locate.1.gz

Use which Command find whereis command

[root@localhost ~]# which whereis
/usr/bin/whereis

Use locate Command find rm command

[root@localhost ~]# locate rm

2、find Command to use ：

Use find Command to find all ordinary files in the current path

[root@localhost test2]# find . -type f
./new_test1.txt
./text.txt
./test111symb.txt
./text111.txt

Use find Command to find... In the current path file1.txt,file2.txt,file3.txt

[root@localhost ~]# find . -name file*
find: paths must precede expression: file5
Usage: find [-H] [-L] [-P] [-Olevel] [-D help|tree|search|stat|rates|opt|exec] [path...] [expression]

Use find The command to find the file owner is root The ordinary documents of

[root@localhost ~]# find . -user root -type f
./.bash_logout
./.bash_profile
./.bashrc
./.cshrc
./.tcshrc
./.cache/dconf/user
./.cache/event-sound-cache.tdb.bcb77bbd33b940cf88ba92dcc3c5795c.x86_64-redhat-linux-gnu

Use find The modification time under the command is 1 Ordinary documents within days

[root@localhost ~]# find . -mtime -1 -type f
./.cache/tracker/meta.db
./.cache/tracker/meta.db-wal
./.cache/tracker/meta.db-shm
./.cache/tracker/locale-for-miner-apps.txt
./.cache/gnome-software/shell-extensions/gnome.json
./.cache/gnome-software/shell-extensions/extensions-web.xmlb
./.cache/gnome-software/odrs/ratings.json
./.config/ibus/bus/bcb77bbd33b940cf88ba92dcc3c5795c-unix-0
./.config/dconf/user

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

[root@localhost ~]# cut -f1 cut_data.txt
No
1
2
3
4

Use the default delimiter to cut the contents of the file , And output the first field and the third field after cutting

[root@localhost ~]# cut -f1,3 cut_data.txt
No  Score
1   20
2   80
3   90
4   60

Cut by byte ： Output the first byte to the second byte of the cut 10 Bytes of content

[root@localhost ~]# cut -b 1-10 cut_data.txt
No  Name    Sc
1   zhang   20
2   li  80
3   wang    90  
4   sun 60

Cut by character ： Output the first character and the second character after cutting 5 Characters to content

[root@localhost ~]# cut -c 1-5 cut_data.txt
No  Na
1   zha
2   li  
3   wan
4   sun

Cut according to the specified delimiter ： The contents are as follows , Output the contents of the first and third fields

No|Name|Score

1|zhang|20

2|li|80

3|wang|90

4|sun|60

[root@localhost ~]# cut -d "|" -f1,3 cut_data2.txt 
No|Score
1|20
2|80
3|90
4|60

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

[root@localhost ~]# uniq uniq_data.txt
Welcome to linux
Windows
Mac
Linux

Use uniq The command outputs only duplicate lines

[root@localhost ~]# uniq -D uniq_data.txt
Windows
Windows
Mac
Mac

Use uniq The command outputs non repeating lines

[root@localhost ~]# uniq -u uniq_data.txt
Welcome to linux
Linux

Use uniq The command counts the number of repetitions

[root@localhost ~]# uniq -c uniq_data.txt
      1 Welcome to linux
      2 Windows
      2 Mac
      1 Linux

5、sort command

Given file content num.txt,args.txt

num.txt:

1

3

5

2

4

args.txt:

test

args1

args2

args4

args4

args3

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

[root@localhost ~]# sort num.txt > sorted_num.txt
[root@localhost ~]# cat sorted_num.txt
1
2
3
4
5

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

[root@localhost ~]# sort args.txt > sorted_args.txt
[root@localhost ~]# cat sorted_args.txt
args1
args2
args3
args4
args4
test

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

[root@localhost ~]# sort num.txt args.txt > sorted_merge.txt
[root@localhost ~]# cat sorted_merge.txt
1
2
3
4
5
args1
args2
args3
args4
args4
test

Yes args.txt After sorting, de re output

[root@localhost ~]# sort args.txt | uniq 
args1
args2
args3
args4
test

Merge sorted_args.txt and sorted_num.txt And output

[root@localhost ~]# sort -m sorted_num.txt sorted_args.txt
1
2
3
4
5
args1
args2
args3
args4
args4
test

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

[root@localhost ~]# sort info_txt -k2
2   li  80
No  Name    Score
4   sun 60
3   wang    90  
1   zhang   20

6、tr Command to use

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

[root@localhost ~]# cat tr_data.txt | tr 'n-z' 'N-Z'
abcdefghijklmNOPQRSTUVWSYZ

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

[root@localhost ~]# cat tr_data2.txt | tr '1-6' '\0'
hello  world 

take hello 123 world 456 Replace the letters and spaces in , Just keep the numbers （ Use wildcard characters when using a body ）

[root@localhost ~]# cat tr_data2.txt | tr 'a-z' '\0'
 123  456

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

[root@localhost ~]# vim word_count.txt
#  Statistics by byte 
[root@localhost ~]# wc -c word_count.txt
50 word_count.txt
#  Count by word 
[root@localhost ~]# wc -w word_count.txt
10 word_count.txt
#  Count by line 
[root@localhost ~]# wc -l word_count.txt
10 word_count.txt