1. View file content
1. Check line 6 of the /etc/passwd file
Use head and tail to operate. "head -n 6" means to view the contents of the first 6 lines, and "tail -n 1" means to view one line from back to front.
2. View the lines starting with SELINUX in /etc/selinux/config
Use groups to operate
3. Find the line ending with no in /etc/ssh/sshd_config
Using group representation, "group n$" means finding lines ending with n
4. Filter /etc/ssh/sshd_config lines containing numbers
Use "group [0,9]" to find numbers from 0 to 9
2. Text processing commands
1. View the contents of the first column of the /etc/passwd file with: as the delimiter, and sort them in reverse alphabetical order.
"cut" delimits the character, "-d:" defines the delimiter character, here is ":", "-f1" needs to take which field, here is the "first line".
"sort -r" sorts in reverse order.
2. Use the cut command to cut and display the IP address of the current host.
3. Copy and move
1.
(1) Create a subdirectory dir in the /test directory and copy /etc/passwd to the directory
(2) Copy the /etc/ssh/sshd_config file to the /test directory
(3) Copy /etc/yum.repos. Copy the d/ directory to the /test directory
(4) Copy the /etc/hosts file to the /test directory
(5) Copy the /etc/hostname file to the /test directory
(6) Move the /test/sshd_config file to /test/ dir directory and renamed it to sshd.conf.
These questions all have the same purpose, so I wrote them together.
It's all a "cp" copy and move.
4. File search
1. In the $HOME directory and its subdirectories, search for files that were changed 2 days ago
Through the "find" method, "-mtime" indicates the time when the content was modified, and "-2" indicates the file name within 2 days or less.
2. Look for files starting with host in the /etc/ directory
Use "-name" under "find" to match names, and "host*" indicates files starting with host.
3. Find directory files under /test/
4. In the /test directory and subdirectories, search for files exceeding 2KB
"-size" means the file size
"+2k" means greater than 2KB
5. Packaging and compression
1. Compress all files and folders in the /test directory into the myfile.zip file
Use "zip" to compress
and view the results:
2. Unzip the myfile.zip file to /opt
Unzip using "unzip".
3. Pack all the files in the /opt directory and compress them with gzip into /test/newfile.tar.gz
First use "cd" to enter the "/opt" directory, and then use "tar" to package.
4. Check what files are in the /test/newfile.tar.gz file?
View via "tvf".
5. Download newfile.tar.gz to the windows client host
6. In the /test directory, back up all files under /etc and retain their permissions
Backup via "-cvf".
