Services

What is a Linux service?

Description

• Linux services are applications or processes that run in the background either because they're actively doing something or waiting to do something.

• An example service would be OpenBSD Secure Shell server, a service that allows one to connect to the system via SSH.

Interacting with Services

• systemctl is the system manager tool which is responsible for managing services.

• systemctl list-unit-files - View all services available.

UNIT FILE                                  STATE           PRESET  
proc-sys-fs-binfmt_misc.automount          static          -       
-.mount                                    generated       -       
dev-hugepages.mount                        static          -       
dev-mqueue.mount                           static          -       
home.mount                                 generated       -       
proc-sys-fs-binfmt_misc.mount              disabled        disabled
run-vmblock\x2dfuse.mount                  enabled         enabled 
[SNIP]

• systemctl status ssh - Gets information on the status of ssh

○ ssh.service - OpenBSD Secure Shell server
     Loaded: loaded (/lib/systemd/system/ssh.service; disabled; preset: enabled)
     Active: inactive (dead)
       Docs: man:sshd(8)
             man:sshd_config(5)

• sudo systemctl start ssh - Starts the ssh service

• sudo systemctl stop ssh - Stops the ssh service

• sudo systemctl enable ssh - Enables the ssh service to run on system boot

• sudo systemctl disable ssh - Disables the ssh service from running on system boot