Crontab Introduction to use

1. Add the current user name (preferably with a normal user) to the/etc/cron.allow, with the carriage return as the delimiter; 2. Create a run script in which the export PATH defines the environment variables you need; 3. Call the script in CRONTAB-E; examples are as follows: 59 23 1 5 * Mail Kiki

The meanings of these six linked fields bits are:

Representing meaning	Minutes	Small Hours	Date	Month	Week	Instructions
Digital Range	0-59	0-23	1-31	1-12	0-7	Yes, just order.

What's more interesting is that "Week" Oh! The number of weeks is 0 or 7, which means "Sunday"! In addition, there are some helper characters, probably the following:

Special characters	Representing meaning
* (Star)	Mean to accept at any moment! For example, the day, month, and week of the example are all *, which means that "every day, no matter what the month, and the days of the worship of a few 12:00 are executed after the instructions"!
, (tease)	Represents the meaning of the separation period. For example, if the work to be done is 3:00 and 6:00, it will be: 0 3,6 * * Command time parameters there are five linked fields, but the second linked fields is 3,6, representing 3 and 6 are suitable!
-(minus)	Represents a period of time, for example, 8 to 12 points each hour of the 20 minutes to do a job: 8-12 * * Command Aberdeen see the second linked fields become 8-12 Oh! On behalf of the 8,9,10,11,12 are meant to be used!
/n (Diagonal)	That n stands for numbers, which means "every n compartments", for example, every five minutes: */5 * * * * command is simple! with * and/5 to match, also can write 0-59/5, the same meaning!

Crontab Introduction to use