Linux course

1. Set the command input prompt line format: "Username: Current directory $”

2. Set the command input prompt line format: “ current system time - User#” (Hint: Shell will interpret the quoted string as a command via the backquote ';”).

3. Optional: Modify the value of the environment variable PATH, and ask to attach the current user home directory path to the end of the variable.

4. Use the at command to broadcast to the system all users 1 minute after the current time broadcast "ldello" information.

5. Please customize the following scheduled tasks: Set the file tmp (created by yourself) in the user's home directory to tmpbackup after two minutes of the current time, and check the actual effect.

6. Display the 10 messages that the root user has recently logged in to the current system.

7. Count the number of recent system reboots.

8. Display the online status of the root user as of 8:00 today

9. Set the 5-second interval to view the basic status of the system. Information indicates that the process occupies the highest CPU ratio and which process occupies the most memory.

As shown in the figure, the process with the process number 4698 has the highest CPU proportion, and the process with the process number 4698 and 1 takes up the most memory.

10.View and indicate the current system. The process with the lowest priority.

As shown in the figure, the process with a good process of 3 has the lowest priority

11. Jump to the system log directory and indicate which of the log directories is recorded. Types of logs.

messages: basic operation information of the system, the syslog process is responsible for recording;

wtmp: record the binary file of the user login information, use the last command to get the file content;

dmesg: Logs about device information can be viewed with dmesg;

secure: System security information record.

cron: Logs about the scheduled task process cron

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