Linux system daemon and Scheduled tasks

Source: Internet
Author: User
Tags set time

the relationship between procedures and processes

* Program

• Executable code and data stored on hard disks, discs, and other media

• Statically saved code

* Process

• Program code running in CPU and in memory

• Dynamically executed code

• Parent, child process

> Each process can be created in one or more Process

*pid No.

• Unique identification of each process, usually used as the end process

* Process Query

PS Pgrep

Top Pstree

* Process Management

CTRL + Z foreground process into the background

CTRL + C End Process

Jobs View Background Process

fg# The background # process is running in the foreground

bg# running the background # process in the background

& Run the process directly in the background

Kill, Killall End Process

Scheduled Task management

*at command

One-time Scheduled tasks

Service script:/ETC/INIT.D/ATD

Format at [hh:mm] [YYYY-MM-DD]

At>ctrl+d End Edit

* Enquiry and deletion

Atq

Atrm

At–c # Viewing the contents of a specified scheduled task


*crontab command

Periodically schedule tasks to execute user-made commands in a pre-set time period

Service Script Name:/etc/init.d/crond

Primary profile global configuration file/etc/crontab

The system default configuration file is located in/etc/cron.*/

User-defined profiles are located in the/var/spool/cron/user name

650) this.width=650; "Src=" https://s4.51cto.com/wyfs02/M02/9A/62/wKioL1lU9xvwz6ykAADbdTbdc-E791.png-wh_500x0-wm_ 3-wmp_4-s_3091450118.png "title=" qq picture 20170629204750.png "alt=" Wkiol1lu9xvwz6ykaadbdtbdc-e791.png-wh_50 "/>

Linux system daemon and Scheduled tasks

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.