Linux: Routine work

What is routine work?

In fact, for routine work, it is necessary to work periodically in the current environment.

Under Linux, there are 2 types of routine work:

One is sudden, and after that, there's no such thing.

At:at is a command that can handle the end of a schedule only once, but the service must be ATD to execute at.

In some Linux versions this service is not turned on by default, so we need to open this service.

The other is routine, that is, every certain period of time to do things:

Crontab:crontab the work of this command lock setting will be cycled all the way down. The time that can be cycled is minutes. Hours. Weekly. monthly or yearly. Crontab In addition to the use of command execution, you can also edit/etc/crontab to support,

Then we'll look at the usual routine work under Linux:

1. Rotation of the log file (log rotate);

2. Log file Analysis Logwatch tasks:

System software problems, hardware errors, and so on most of the information will be recorded in the log file, so Logwatch is the active analysis of log file information to the software/hardware error content monitoring.

3. New database of locate;

The establishment of 4.whatis database;

5.RPM The new software log file;

6. Delete temporary files;

7. Analytical behavior related to playing a service;

Here's a look at working with Linux:

ATD Start-up and at operation mode;

Open at:

Under Root user rights:

/ETC/INIT.D/ATD restart

Use:

at [-MLDV] Time

-m:at work is completed, even if no output information, in the form of an email notification that the user's work has been completed

-L: Lists all the at jobs on the system

-D: Cancel a job in the schedule

-V: You can list the at worksheet with a more obvious time format

-C: You can list the actual command contents of the work that followed

TIME:HH:MM 04:00 hh:mm yyyy-mm-dd 04:00 2009-03-17

Hh:mm[am|pm][month][date] 04pm March 17

hh:mm[am|pm]+ Numer[minutex|hours|days|weeks] Now + 5 minutes 04pm + 3 days

ATQ show current at list, ATRM [Jobnumber], delete at item

Routine work schedule for loop execution:

User's settings:

/etc/cron.allow can be used when added, not available

/etc/cron.deny writes are not available and can not be used.

To add a recurring routine work:

crontab [-u username] [-l|-e |-r]

-u:root to do this task, but also to help other users new/delete crontab work schedule;

-E: Edit crontab work content:

-L: Check the contents of crontab

-R: Delete all, delete the words please-e edit

Edit syntax:

Photo by: Brother Bird's Linux private cuisine:

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Then let's try it out:

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*/5 * * * * echo Hello >/dev/pts/0

Sun and Moon Week #分 [========== command string =====]

is to print hello to the current terminal every 5 minutes.

The TTY command queries the current terminal path.

This article is from the "egg-left" blog, please be sure to keep this source http://memory73.blog.51cto.com/10530560/1771639

Linux: Routine work