Learn how to select content to view Linux commands: Detailed explanation of the tail command

Use of the head -n command

 

The head command is used to display the contents of the beginning of the file. By default, the head command displays the first 10 lines of a file.

grammar

head(options)(parameters)

Options

-n<number>: Specify the number of lines to display the header content;
-c<number of characters>: Specify the number of characters to display the header content;
-v: always display the header information of the file name;
-q: Do not display header information for filenames.

parameter

file list: Specifies the list of files to display the header content.

 

 

 

 

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Linux command: detailed explanation of tail command

 

Overview: The tail command displays the block at the end of the file, and you can also view the online log

1. Format

　　tail [parameter] [file]

2. Parameters

　　-f loop read

　　-q do not display processing information

　　-v display detailed processing information

　　-c <number> number of bytes to display

　　-n<number of lines> Display the number of lines

3. Examples

#Create file tail.txt
cat > tail.txt<<EOF
1
2
3
4
5
6
7
8
9
10
11
12
EOF

 

#Display last 5 lines
tail-n  5 tail.txt

#display last 5 bytes
tail -c  5 tail.txt

 

#loop through
tail -f tail.txt

Overview: The tail command displays the block at the end of the file, and you can also view the online log

1. Format

　　tail [parameter] [file]

2. Parameters

　　-f loop read

　　-q do not display processing information

　　-v display detailed processing information

　　-c <number> number of bytes to display

　　-n<number of lines> Display the number of lines

3. Examples

#Create file tail.txt
cat > tail.txt<<EOF
1
2
3
4
5
6
7
8
9
10
11
12
EOF

 

#Display last 5 lines
tail-n  5 tail.txt

#display last 5 bytes
tail -c  5 tail.txt

 

#loop through
tail -f tail.txt