Description of startup items under ubuntu

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Here,UbuntuThe system is missingRHIn the systemChkconfigCommand!

Use some gadgets to manageUbuntuStartup options:
Gadgets Rcconf:
# Sudo apt-get rcconf
# Sudo apt-get install rcconf
Run the following command under root:# Sudo rcconf
More comprehensive tools:Sysv-rc-conf
# Sudo apt-get update
# Sudo apt-get install sysv-rc-conf
Run:# Sudo sysv-rc-conf
You can also directly add the startup program, for example, add/etc/init. d/red5 to the Automatic startup list of the system:
#sudo sysv-rc-conf red5 on
For other usage methods, see google: Ubuntu: sysv-rc-conf.

You can also directly modify
Directly change/etc/rc0.d ~ /Etc/rc6.d and/etc/rcS. d,SStart,KIndicates that the instance is not started,
For example, if you want to disable auto start of Red5, you only need to # sudo mv/etc/rc2.d/S20red5/etc/rc2.d/K20red5.

Ubuntu automatically starts the program

First, all the services started randomly in linux are in/etc/init. d. All the files in this folder are script files (in simple words, the script program writes the program to be run to a file so that the system can execute it in order, similar to windows autorun. in addition, there are folders such as rc1.d, rc2.d to rc6.d In the/etc folder, which are different runlevels in linux, generally, the running level of multiple users in X windows is 5th, that is, rc5.d. The script file in this folder is the service program to be started randomly when the script file is 5th. Note that in each rc
(1-6 ). the files in the d folder are all/etc/init. A soft connection to the files in the d folder (similar to the shortcut in windows), that is, in/etc/init. the d folder contains all the service programs, and each rc (1-6 ). d. Only link it to start the desired service program!

To start scim (a program), we first need to know where the scim program is. We can use the locate command to find it. scim is in/usr/bin/scim, the usr table indicates that the user belongs to the user, and bin indicates that the program can be executed in linux. In this way, I can write a script program, put it in/etc/init. d, and then make a corresponding soft link in rc5.d.

This script is actually very simple, just two lines:

#! /Bin/bash

/Usr/bin/scim

The first line is to declare the terminal used to run the script, and the second line is the command to run.

Note that in rc5.d, the name of each link starts with S or K, K starts with a random start. In this case, you can know which service I want to start at random, and change the first letter K to S. Of course, after changing S to K, this service cannot be started randomly. Therefore, we need to name this link SXXX so that the system can start it at random.

In RH, rc. local is the last script file started by default. Therefore,

If you want to start the instance at random, add/usr/bin/scim to the end of rc. local.

Linux Automatic startup program

1. automatically run the program at startup

After Linux is loaded, it initializes the hardware and device drivers, and then runs the first process init. Init starts other processes based on the configuration file. Normally, the modification is placed in/etc/rc or/etc/rc. d or/etc/rc ?. The script file in the d directory can enable init to automatically start other programs. For example, edit/etc/rc. d/rc. local file (this file is usually the last script started by the system). Add "xinit" or "startx" at the end of the file to directly enter the X-Window after the file is started.

2. automatically run the program upon Logon

When a user logs on, bash automatically runs the global logon script:/ect/profile created by the system administrator. Bash then searches for one of the three special files in sequence in the user's starting Directory:/. bash_profile,/. bash_login, And/. profile, but only executes the first one found.
Therefore, you only need to add commands to the above files as needed to automatically run certain programs (similar to Autoexec. bat in DOS) during user logon ).

3. automatically run the program upon logon.

When you log out, bash automatically runs the personal logout script/. bash_logout. For example /. in bash_logout, add the command tar-cvzf c. source. tgz *. c, the "tar" command is automatically executed every time you log out to back up *. c file.

4. Periodically run the program automatically

Linux has a daemon called crond. Its main function is to periodically check the content of a group of command files in the/var/spool/cron directory, and execute the commands in these files at the specified time. You can use the crontab command to create, modify, and delete these command files.

For example, create a crondFile with the content "00 9 23 Jan * HappyBirthday". After running the "crontab cronFile" command, every time the system automatically executes the "HappyBirthday" program at AM on March 23, lunar January ("*" indicates that no matter the day of the day is the day of the week ).

5. automatically run the program once at a scheduled time

Scheduled command execution at is similar to crond (but it is only executed once): The command is executed at a given time, but is not automatically repeated. The at command is generally in the format of at [-f file] time. All commands in the file are executed at the specified time. You can also enter the command directly from the keyboard:

$ At 12: 00
At> mailto Roger-s "Have a lunch" <plan.txt
At> Ctr-D
Job 1
At, an email entitled "Have a lunchtasks, containing the plan.txt file content was automatically sent to Roger .?
At, February 9, an email entitled "Have a lunch.pdf containing the plan.txt file was automatically sent to Roger. Er. Ger. Er.