java displays text file content displays file display content
Common Linux commands--file related operations
1, user switching
su(switchuser)
2, display the file list of the current directory
ls(list)
ls-l
ls-a(all)
ll
ll-a
On Linux, hidden files begin with "."
3, directory operations
Switch directory: cd(changedirectory)
Display the current directory: pwd(printworkingdirectory)
Create directory: mkdir(makedirectoriy)
-pIf the parent directory does not exist, first generate the parent directory (parents)
cp copy file or directory (copy)
-r recursive processing, copy the files and subdirectories in the specified directory together (recursive)
mv Unicom file or directory, file or directory rename (move)
rmdir delete empty directory (removedirectoriy)
rm delete file(remove)
-rDelete all files in the directory at the same time (recursive)
-f force delete file or directory (force)
Ordinary users will not receive any prompt when deleting
However, when the super administrator deletes, he will be prompted
Additional point: cd~can quickly reach the home directory
4, Editing of file content-VI, VIM (emphasis)
work flow chart:
Insert command parsing:
a: Add text after the current character;
A: Add text at the end of the line;
i: Insert text before the current character;
I: Insert text at the beginning of the line;
o: Insert a blank line before the current line;
O: Insert a blank line after the current line;
Shortcut commands:
Location command
: setnumber displays line number
: setnonumber cancels the line number
:n to the nth line of text
gg to the first line of text
GTo the last line of text
Delete command
x: Delete the single character where the cursor is located
dd:delete the line
Undo command
uundo,cancel the previous operation
Ctrl rredo, return to before undo
Copy command
yy p
5, Viewing and Statistics of File Content
touch creates an empty file
Display file content:
cat displays text file content
moreDisplay text file content in pagination
less
head and tail View the content at the beginning or end of the text
head-n3java.txtView the first 3 lines of the java.txt file
wc counts the number of lines, words, and characters of text (wordcount)
-m counts the number of text characters
-w counts the number of text phrases and recognizes spaces
-lCount text lines
6, File merging and redirection
The contents of the merged files are output together, cat1.txt2.txt
Merge files: cat1.txt2.txt>3.txt
As a standard input,
cat>1.txt
cat>>1.txt
>This is a symbol for redirecting output
Case: Quickly clear the contents of a file
Use redirection method
>1.txt
7, File search
findFind the specified file in the file system
find/usr/local/-nameword.txt
8, Compression, decompression and packaging of files
Command Overview
gzip: compressed (decompressed) file, the suffix of the compressed file is gz
Bzip2: Compressed (decompressed) filelinux decompresses the zip file, the suffix of the compressed file is bz2
Tar: Packaged file or directory
Command Interpretation
Interpretation of gzip command: gzip[option] file name to be compressed (decompressed)
-dDecompress the compressed file
-lFor compressed files, display the size of the compressed file, the file size before compression, compression ratio, etc.
-num uses the specified number num to adjust the compression rate linux decompress zip file linux system introduction linux operating system tutorial, -1 or --fast indicates the fastest compression method (but the compression ratio is low),
-9 or --best indicates the slowest compression method (high compression ratio). The system default value is 6
bzip2 command interpretation: bzip2[option] file name
-dDecompression
-zCompression
-num Same as above
Interpretation of Tar command: tar[option] package file name to be packaged file 1 to be packaged file 2
-c build a package file create
-xUnpack a package fileextract
-zCompress files with gzip
-jUse bzip2 to compress files
-v Compression process display file
-f uses the file name, and the file name must be followed immediately after f
Case:
Implementing the packaging and unpacking of files
Realize compression and decompression of files
gzip1.txt compressed file
gzip-d1.txt.zip decompressed file
tar-cf33.tar1.txt2.txt//Packaging file
tar-xf33.tar//Unpack file
gzip33.tar//Compressed package file tar.gz
tar-zcf33.tar.gz1.txt2.txt//Package and compress 1.txt and 2.txt into 33.tar.gz
tar-zxf33.tar.gz//Decompress 33.tar.gz
9, pipeline command
Command format:
command1|command2
Example:
ls-l/usr/bin|less
ls-l/usr/bin|grepless
The standard output of one command can be piped to the standard input of another command:
grep is a very powerful program, used to find matching text in files
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