Modify the contents of /etc/crontab file directly, and the scheduled task will not take effect

direct writing /etc/crontab  Document content is invalid .

service crond reload/restart It doesn't work .

direct writing crontab When you file , You need to specify the executing user , And the top environment variable Can't delete .

Such as ：

# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/
*/1 * * * * root date > /root/test.txt

If no running user is specified in the scheduled task , Such as ：

*/1 * * * * date > /root/test.txt

This command will not be executed .

Reproduced in :https://blog.51cto.com/zhangxingnan/1609879