Shell combined with crontab timer

crond service

In daemon mode without the need for human intervention in the process down a series of operations and service instructions

• Check the service status
  • systemctl status cron.service
• Out of service
  • systemctl stop cron.service
• Start Service
  • systemctl start cron.service
• Restart Service
  • systemctl restart cron.service

crontab

• Instruction format: crontab [options]
• -l: List crontab currently exist
• -e: Edit crontab
• -r: Remove all tasks

• Content format:

  *  *  *  *  * 级别 命令(shell脚本绝对路径)
  分 时 日 月 周

  Examples of crontab time

每分钟(10:01,10:02 ...)
* * * * *   或  */1 * * * *

每小时
0 * * * *

每天
0 0 * * *

每周
0 0 * * 0

每月
0 0 1 * *

每年
0 0 1 1 *

每天早上６点
0 6 * * *

每２小时
0 */2 * * *

每小时10分，40分
10,40 * * * *

每天下午4,5,6点的 1,2,3,4,5min
1,2,3,4,5 16,17,18 * * *

Examples

Each additional minute to the log file one line hello world

Write test.sh

echo "hello world " >> /var/test.logs

Write crontab step

1.查看当前任务列表
crontab -l

2.进入crontab编辑界面
crontab -e

3.末尾加入
* * * * * sh test.sh的绝对路径