Linux Experiment Report (3) - Scheduled Task Management - 2021.5.22

1. Configuration requirements:

• Virtual machine VM15.0 and above
• centos7.0 version
• windows7 or windows10 host

2. The purpose of the experiment

• Master the syntax for writing scheduled task statements
• Master the skills of using scheduled tasks to improve execution efficiency
• Learn how to schedule tasks in the production process

3. Experimental requirements: (Root)

A crontab scheduled task list is set up by the root user to complete the following tasks:

crontab -e

1. The sshd service is automatically turned on at 6:30 every morning, and the sshd service is turned off at 23:30.

30      6        *      *        *      /usr/bin/systemctl start sshd
30      23       *      *        *      /usr/bin/systemctl stop sshd

2. The data in the public directory /var/ftp/pub of the FTP server is emptied every 5 days.

0       *        */5    *        *      /usr/bin/rm –rf /var/ftp/pub/*

3. Restart the httpd service every Saturday at 6:15.

15      6        *      *        6      /usr/bin/systemctl restart httpd

4. Every Monday, Wednesday, and Friday at 22:30 pm, use the tar command to automatically back up the /etc/httpd directory.

30      22       *      *        1,3,5  /usr/bin/tar jcvf httpd.tar.bz2 /etc/httpd

5. Configure a scheduled task for the 180xname user: execute /bin/echo hello at 13:40 every day

crontab -e -u 1802huangjie
# 40      13      *       *       *       /bin/echo hello

6. Set a scheduled task for user lisi, copy the contents of the /etc/passwd file to the host directory at 23:55 every Sunday night, and save it as pwd.txt

crontab -e -u lisi
# 55	23      *       *       7       /usr/bin/cp /etc/passwd /home/lisi/pwd.txt

7. Set up a scheduled task for user wangwu, backup /var/log/message to the log-bak directory in your home directory every 2 hours between 8:00 and 18:00 on weekdays

crontab -e -u wangwu
# *       8-18/2          *       *       *       /usr/bin/cp /var/log/message /home/wangwu/log-bak

8. View the contents of the root user's scheduled tasks list

crontab -l

9. View the contents of the scheduled tasks list of users zhangsan and lisi

# 查看用户zhangsan的计划任列表的内容
crontab -l -u zhangsan

# 查看用户lisi的计划任列表的内容
crontab -l -u lisi

10. Delete the scheduled task of 180xname

crontab -r -u 1802huangjie

4. Previous: Linux Experiment Report (2) - Disk Storage Management

Linux Experiment Report (2) - Disk Storage Management