Summary of frequently used commands for Linux file operations

0. New operation:

mkdir abc #Create a new folder touch abc.sh #Create a new file

1. View Operation

View the catalog:

ll #Display directory file details

View the file contents:

cat|head|tail Commands

cat abc.txt #View the content of abc head -5 abc.txt #View the first 5 lines of abc. The default is 10 lines. The meanings of the tail [options] file name options are as follows:
+num: Start displaying from line num onwards -num: Start displaying from num lines from the end of the file. If the num parameter is omitted, the system default value is 10.
-f: Circular reading. For example, when viewing the server log, you can observe the last part of the #filename file displayed on the screen in real time and refreshed continuously.
tail -f filename 
#View the last 20 lines tail -f filename

more command:

The more command displays one screen of information at a time. If the information is not displayed completely, "-More-(xx%)" will appear at the bottom of the screen.

At this time, press the Space key to display the next screen content;

Press the "Enter" key to display the next line of content;

Press the B key to display the previous screen;

Press the Q key to exit the more command.

​ less command: Similar to the more command, but more powerful than the more command. In many cases, you must use less, such as pipes. For example:

ll /etc | less

stat command:

View detailed information about the file, such as creation and modification time, size, etc.

[root@localhost zx]# stat index.html File: "index.html" Size: 29006 Blocks: 64 IO blocks: 4096 Normal file device: fd00h/64768d Inode: 17589607 Hard links: 1 Permissions: (0644/-rw-r--r--) Uid: ( 0/root) Gid: ( 0/root) Environment: unconfined_u:object_r:home_root_t:s0 Last access: 2019-09-02 21:47:41.824053666 +0800 Last change: 2019-09-02 21:44:33.588587500 +0800 Last modification: 2019-09-02 21:44:33.588587500 +0800 Creation time: -

du command:

Option: -h Display in appropriate units (automatically select kb or M units based on the file size)

[root@localhost zx]# du -h index.html 
32K index.html

2. Delete operation

rm -f aa.txt #Force deletion of aa.txt
rm -rf fileDir #Force deletion of the fileDir folder and all files in it

3. Copy Operation

Copy on the same machine:

cp: copy files or directories

grammar:

cp [options] source dest

-a: This option is usually used when copying a directory. It preserves links, file attributes, and copies all the contents under the directory. Its effect is equal to the dpR parameter combination. -d: Keep links when copying. The link mentioned here is equivalent to the shortcut in the Windows system. -f: Overwrite an existing target file without prompting. -i: Contrary to the -f option, a prompt is given before overwriting the target file, asking the user to confirm whether to overwrite. If the answer is "y", the target file will be overwritten. -p: In addition to copying the contents of the file, the modification time and access permissions are also copied to the new file. -r: If the given source file is a directory file, all subdirectories and files under the directory will be copied. -l: Do not copy the file, just generate a link file.

Example:

#Copy ../html/index.html to the current directory cp ../html/index.html . 
#Copy the files and subdirectories in the ../html/ directory to the current tt directory. If tt does not exist, it will be automatically created cp -r ../html/ tt/  
#Copy the file file to the directory /usr/men/tmp and rename it to file1
cp file /usr/men/tmp/file1 
 
#If the dir2 directory already exists, you need to use cp -r dir1/. dir2
#If you use cp -r dir1 dir2 at this time, the dir1 directory will also be copied to dir2, which obviously does not meet the requirements.
ps: Just change dir1 and dir2 to the corresponding directory paths.

Remote replication

#Copy the test.txt in the current directory to the /zx directory of the remote 111.12 machine scp test.txt [email protected]:/zx

#Copy test.txt to the remote user's root directory and name it textA.txt
scp test.txt [email protected]:testA.txt

#You can also not specify a user and enter it in the subsequent prompts, as follows:
scp test.txt 192.168.111.12:/zx

#Copy from remote to local: -r is used to recurse the entire directory scp -r remote_user@remote_ip:remote_folder local_path

4. Mobile operation:

The move operation can be understood as copying the file and then deleting the original file.

eg1:

mv /zx/soft/* . #Copy all files in the /zx/soft directory to the current directory mv a.txt ./test/a.txt #Copy the current directory a.txt to the current test directory.
mv /zx/soft/ /tmp/soft #Copy the folder to /tmp/. Make sure tmp exists.

5. Rename operation:

Renaming still uses the move operation command, for example:

#Rename directory (file) A to B
mv AB
#Move the /a directory (file) to /b and rename it to c. Make sure the b directory exists.
mv /a /b/c
#Move the current test1 directory to the current test directory and name it b
mv ./test1 ./test/b

6. Decompression and compression operations

tar
-c: create a compressed archive -x: decompress -t: view the contents -r: append files to the end of the compressed archive -u: update files in the original compressed package

These five are independent commands, and one of them is required for compression and decompression. They can be used in conjunction with other commands, but only one of them can be used. The following parameters are optional when compressing or decompressing archives as needed.

-z: has gzip attribute -j: has bz2 attribute -Z: has compress attribute -v: displays all processes -O: decompress the file to standard output

The following parameter -f is required

-f: Use the file name. Remember, this parameter is the last parameter and can only be followed by the file name.

3. Examples:

tar -cf all.tar *.jpg This command packs all .jpg files into a package named all.tar. -c means to generate a new package, and -f specifies the file name of the package. tar -tf all.tar This command lists all files in the all.tar package. -t means to list files. tar -xf all.tar This command extracts all files in the all.tar package. -x means to extract. Compression tar –cvf jpg.tar *.jpg //Package all jpg files in the directory into jpg.tar eg2: tar -xzf nginx-1.14.0.tar.gz //Unzip to the current directory tar -zxf nginx-1.14.0.tar.gz -C /usr/local/nginx #Unzip to the corresponding directory eg3: tar -zxvf nginx...tar.gz #Unzip and display the process

Note: Some compression programs prompt that the command cannot be found and need to be installed, for example:

yum install unzip
or on ubuntu:
apt-get install unzip

IV. Conclusion

1. Decompress *.tar with tar –xvf 2. Decompress *.gz with gzip -d or gunzip 3. Decompress *.tar.gz and *.tgz with tar –xzf 4. Decompress *.bz2 with bzip2 -d or bunzip2 5. Decompress *.tar.bz2 with tar –xjf 6. Decompress *.Z with uncompress 7. Decompress *.tar.Z with tar –xZf 8. Decompress *.rar with unrar e 9. Decompress *.zip with unzip

When decompressing, sometimes you don’t want to overwrite existing files, so you can add the -n parameter

unzip -n test.zip unzip -n -d /temp test.zip Just check which files are included in the zip archive without decompressing it unzip -l test.zip Check that the displayed file list also includes the compression ratio unzip -v test.zip Check if the zip file is damaged unzip -t test.zip If the same file already exists, ask the unzip command to overwrite the original file unzip -o test.zip -d /tmp/ Example: eg1: unzip mydata.zip -d mydatabak #Unzip to the mydatabak directory 10. xz

This is a two-layer compression method, the outer layer is xz compression method, and the inner layer is tar compression method, so decompression can be achieved in two steps

 $ xz -d node-v6.10.1-linux-x64.tar.xz
 $ tar -xvf node-v6.10.1-linux-x64.tar

7.Upload file tool

To upload some files from the local Windows to the remote Linux server, you can use xshell's xftp or the following small tool lrzsz, which is more convenient to use.

yum install lrzsz #安裝工具

Common commands:

sz dist.zip #Download the file dist.zip to the local machine rz #Open the window and upload the file to the remote server

8.ln, file, and touch commands

ln command: It is used to create link files, including hard links and symbolic links. We often use symbolic links, also called soft links. Soft links are similar to shortcuts in Windows.

Example:

#Create a soft link in the current directory, pointing to /etc/fastab, also named fastab
ln -s /etc/fastab

#Create a soft link pointing to /boot/grub in the current directory and name it gb
ln -s /boot/grub gb

Note: The correct way to delete a soft link is:

rm -rf ./gb

Wrong way:

rm -rf ./gb/

This will delete the original content under grub. Especially for soft links of system files, you must be careful when deleting them.

**file command: **Used to identify the type of file

The file suffix in Linux is only for the convenience of user identification and has no actual restrictive effect. The file command can view the actual type of the file:

file [-bcLz] file|directory

Option description:

File|Directory: The file or directory to be identified -b: When displaying the identification results, do not display the file name -c: Display the execution process -L: Directly display the file type pointed to by the symbolic link file -z: Try to interpret the contents of the compressed file

Example: It can be seen that index.mp4 is essentially an HTML file rather than an mp4 file.

[root@VM_0_13_centos soft]# file index.mp4 
index.mp4: HTML document, UTF-8 Unicode text, with very long lines

**touch command: **Used to change the access time and modification time of a file or directory.

touch [-am] [-t<date time>] [directory|file]

If the specified directory file does not exist, an empty file will be created directly, so touch is also often used to create a blank file.

#Create a new file aa.txt
touch aa.txt

Option description:

-a: only modify the access time -m: only modify the modification time -t: use the specified date and time instead of the system time. For example, you need to modify it to October 20, 2019, 16:38:13. The parameter is: '20191020163813'

Example:

Before modifying, you can check the timestamp of the file: Use the stat command to view

[root@VM_0_13_centos soft]# stat index.html 
 File: 'index.html'
 Size: 17215 Blocks: 40 IO Block: 4096 regular file
Device: fd01h/64769d Inode: 529352 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2019-10-23 15:15:37.280616254 +0800
Modify: 2019-10-23 15:15:37.280616254 +0800
Change: 2019-10-23 15:15:37.290616257 +0800
 Birth: -

Start modifying: Change the access and modification time of the index.html file to the current system time.

touch index.html

9. Find the operation command:

We often forget the files and directories we need to use, so it is extremely necessary to use the search command:

find: search for files or directories (commonly used)

The syntax is as follows:

find [directory...] [-amin <minutes>] [-atime <24 hours>] [-cmin <minutes>] [-ctime<24 hours>][-empty][-exec<execute command>][-fls<list file>][-follow] [-fstype <system file type>] [-gid <group number>] [-group <group name>] [-nogroup] [-mmin <minutes>] [-mtime <24 hours>] [-name <search content>] [-nogroup] [-nouser] [-perm <permission value>] [-size <file size>] [-uid <user number>] [-user <user name>] [-nouser]

Description of several common options:

-size <file size>: Search for files that match the specified size. The file size unit can be "c" for Byte or "k" for KB. If the value is set to "100k", the find command will search for files with a size of exactly 100KB; if the value is set to "+100k", the find command will search for files with a size greater than 100KB; if the value is set to "-100k", the find command will search for files with a size less than 100KB. -user <user name>: Search for files or directories whose owner is the specified user. You can also specify the user number. -name <search content>: Search for the specified content. Use "*" to represent any number of characters in the search content; use "?" to represent any character. -mtime <24 hours>: Search for files or directories whose content has been changed at the specified time. The unit is 24 hours. If it is configured as 2, the find command will search for files whose contents were changed just 48 hours ago. If it is configured as +2, the find command will search for files whose contents were changed more than 48 hours ago. If it is configured as -2, the find command will search for files whose contents were changed within 48 hours. -mmin <minutes>: Find files or directories whose content has been changed within the specified time, calculated in minutes. cmin <minutes>: Search for files or directories whose permission attributes have been changed within the specified time, in minutes. -ctime corresponds to the hour. -amin <minutes>: Search for files or directories that were accessed at the specified time. -atim corresponds to the hour. -perm <permission value>: Search for files or directories that match the specified permission value (see Chapter 6 for permission values). If the configuration is "0700", the find command will search for files or directories with a permission value of exactly "0700"; if the configuration is "+0700", the find command will search for files or directories with a permission value greater than "0700"; if the configuration is "-0700", the find command will search for files or directories with a permission value greater than "0700".

The options are roughly as follows:

1. Search by time range

2. Search by file size

3. Search by file name

4. By others: such as permissions, user groups, types, etc.

Example:

#Start from the root directory and search for directories and files whose names begin with nginx find / -name nginx* 
#Find files with a size greater than 100M find / -size +100M
#Find the files and directories in the /home/zx directory that have been modified within 10 minutes find /home/zx/ -mmin -10

locate: search for files or directories (not commonly used)

locate search content

For example: locate nginx will list all directories and files containing nginx. You can use * or ? Equals matching characters.

The locate command searches very quickly, but because it searches the database, some newly modified files and directories may not be found. You can use the updatedb command to update the database.

which: find a file (not commonly used)

which [file]

The which command only searches in the paths and command aliases defined by the PATH environment variable, so its scope is limited.

whereis : find files (not commonly used)

whichis [-bu] [-B<directory>] [-M<directory>] [-S<directory>] [file]

Common options:

File: Command to find

-b: search only binary files

-u: Find files that do not contain the specified type

-B<directory>: Search for binary files only in the specified directory

-M<directory>: Search for help files only in the specified directory

-S<directory>: Search the source directory only in the specified directory

For example: By default, only the specified directories will be searched (/bin,/etc,/usr)

[root@VM_0_13_centos soft]# whereis nginx
nginx: /usr/local/nginx /usr/local/nginx/sbin/nginx /usr/local/nginx/sbin/nginx.bak

Summarize

The above is a summary of the frequently used commands for Linux file operations introduced by the editor. I hope it will be helpful to everyone. If you have any questions, please leave me a message and the editor will reply to you in time. I would also like to thank everyone for their support of the 123WORDPRESS.COM website! If you find this article helpful, please feel free to reprint it and please indicate the source. Thank you!