Debian Software Package Manager: dselect usage Summary

Content:

Steps for installing a software package using dselect

Select the installation media

Update Available Software Package Database

Select Software Package

Install software package

Configuration package

Delete unused software packages

Exit, complete!

Postscript

About the author

Su baochen (linuxman@sd163.net)

Dselect is an important software package management tool in debian release. It is very powerful and complicated. It may not seem easy to grasp at the beginning. In fact, dselect works in a natural way. As a good teacher, you just need to follow the dselect prompts and install the software package step by step. Let's take a look at how dselect guides us to easily and happily install the debian software package.

1. Use dselect to install the software package

Start dselect and we can see the following interface:

As you can see, the dselect installation package has undergone the following steps:

Confirm the installation media.
Update the installable Software Package database based on the specified installation media.
Select the software package to be installed
Install
Configure the installed software package
Delete unnecessary software packages
Exit

It looks very logical, right? You only need to step by step.

Some people think that dselect is difficult to use, probably because its operation method is not easy to remember. In fact, if you are familiar with one of VI and Emacs, some of the keyboard combinations are similar. For example, in the main interface of dselect, you can select different operation steps (VI processing method) through I and j ), you can also use ^ N and ^ P to move the cursor (the Emacs processing method). Of course, you can also use the cursor key to move the cursor.

2. Select the installation media

Dselect supports multiple installation methods. After [a] cess is selected, the following interface is displayed:

The preceding installation media is self-explanatory. APT mode is recommended. You only need to edit/etc/APT/sources. list file, you can enjoy the software package maintenance that APT brings to you: you only need to set sources. list. Let apt do the rest!

My sources. list is like this:

# See sources. List (5) for more information, especialy
# Remember that you can only use HTTP, FTP or file Uris
# CDROMs are managed through the apt-CDROM tool.
Deb http://http.us.debian.org/debian Sid main contrib non-free
Deb http://non-us.debian.org/debian-non-US SID/non-US main contrib non-free

# Deb http://security.debian.org stable/updates main contrib non-free
# Uncomment if you want the apt-Get source function to work
# Deb-src http://http.us.debian.org/debian stable main contrib non-free
# Deb-src http://non-us.debian.org/debian-non-US stable non-US
# Deb cdrom: [Debian GNU/Linux 2.2 r4 _ Potato _-Official i386 Binary-1
(20011106)]/unstable contrib main non-US/contrib non-US/main
# Deb ftp://ftp.linuxforum.net/debian sid main contrib non-free
# Deb ftp://ftp.linuxforum.net/debian-non-US sid/non-US main contrib non-free

3. Update the available software package Database

Next, update the list database of software packages that can be installed Based on the installation media you select. This step is quite simple. Generally, you only need to press Enter. For example, if apt is used for installation, dselect automatically connects

The debian backup server in sources. list and read the package list data on the server.

If an error occurs, such as a failure to connect to the server when apt is used for installation, dselect will provide error information and some suggestions, ^_^. Is it friendly? Then, after you confirm that dselect returns to the main interface, the cursor is still on the Update line, indicating that the Update operation was not successful. In this case, you can try Update again. If the operation fails after several attempts, it may be because the server is shut down. Try another image. There are many mirror servers.

4. Select a software package

This is the most complex step. Here, dselect needs to complete the following functions:

Select the software package to be installed or deleted
Resolve the dependency between software packages
Resolves conflicts between selected software packages

Dselect's "intelligence" is quite high. With dselect, you only need to answer a few simple questions and the above complex questions can be solved, let's take a look at the installation process of a typical software package.

4.1 help screen

After you press Select, you have to wait (dselect is reading the list of available software packages), and the help screen appears first. It is very important to learn how to use help. All dselect operation methods are in help. The following describes how to use help:

Can I press? To start the help.
After entering help, exit the help with the "space" key.
Use the. Key to read the next screen.

Is it easy? First, you can view the entire help content, but there are only 5 screens in total.

4.2 select a software package

All right, press the space key to exit the help and enter the page for selecting a software package. Seems complicated? Let's explain it.

4.2.1 prerequisites: how to move the cursor

The software package selection interface is divided into the upper and lower sections. The upper part lists the optional software packages, and the lower part provides a simple explanation of the selected software packages.

First, let's take a look at the upper part.

Note that the classification of debian software packages is represented by sections, which are organized into different sections. The moving method of the cursor is difficult here. ^ _ ^ seems simple. In fact, there are still some questions. However, if you are familiar with vi, it will be much simpler. Summary:

Each Software Package occupies one line with the following descriptions:
EIOM, which we will focus on, will be discussed later.
Pri, importance level, which can be divided into Required, Standard, Important, Optional, and Extra.
Section, which is the Section (Category) of the software package)
Package, Package name
Inst. Ver, version number of the installed software package
Avail. Ver, version number of the available software package
Description: a brief Description of the software package.

The above information is easier to understand except EIOM. Let's take a look at the meaning of EIOM:

E-Error flag, Error flag, which can be set:

I-Installed state, the installation status of the current package, which may be set:

O-Old mark, last installation status, which may take the following values:

M-Mark. This installation method may take the following values:

For example, see:

The cvs package shows that:

The EIOM status indicates that the package has not been installed. The version number that can be installed is 1.22.1p1-4. Note: At this time, the O and M signs are both "_", indicating that there is no trace of the software package on your machine, ^ _ ^.
The package belongs to the devel group.

For example:

Bash has been installed. The version is 2.05a-4. Observe the EIOM flag.

4.2.2 start to select the installation package!

After talking about so many keyboard combinations, how can I select a software package for installation? Simply select the required software package or software package group and press the "+" key. If the software package runs smoothly, the selection process ends and you can press the Enter key directly. dselect returns to the main interface and runs the Install function to Install the software.

Example:

It can be seen that when the "+" Key is pressed on the cvs package, the M sign becomes "*", indicating that the package is requested to be installed, and the cursor is moved to the next package, to operate other software packages. If you only want to install the cvs package, press enter to display the following interface:

Do you know how to answer this question? ^_^.

Of course, you can select multiple software packages for installation at a time.

4.2.3 An error occurred!

The software package installation process has minor issues, such as the absence of associated packages and conflicts between software packages. dselect will kindly remind you to make a choice, determine the next step.

For example, when installing the boot-floopies package (Press "+"), the following interface is displayed:

If this is your first time, read it carefully. Otherwise, simply press the Space key to exit the help. The above figure shows that the software package you choose to install must install other dependent packages at the same time or conflict with other software packages. After exiting the prompt page, a list of dependency packages or conflicting packages is displayed. In the lower part of the List window, the detailed information of the software package is provided. In the upper part of the List window, it is the dependent package or conflicting package installation method recommended by dselect, if you agree to dselect's installation suggestions, simply press the Enter key. Otherwise, you can:

View and modify the installation mode of the software package one by one, and then try to press the Enter key to start installation.
Press the "X" Key (exit) to discard the installation of the selected software package and return to the main interface. This means that dselect will restore the installation status of the software package to the status before selection.
Press the "r" Key (revert) to restore to the status before dselect recommendations. The difference with the X key is that the X key is also returned to the main interface.
Press "D" (directly) to reject the recommended dselect installation method. Only the software package you selected is retained. That is to say, none of the dependent packages are installed. I'm afraid it won't work, ^ _ ^.
Press the "U" Key (suggestion) to recover to the dselect recommended installation method, no matter what kind of modification you have made. Therefore, although you can safely change the recommended dselect installation method, you just need to remember the "U" Key, ^ _ ^.
Press "Q" (quit) to force installation in the current setup mode. If the installation method is not recommended by dselect, do you dare? ^_^, Unless you are very familiar with the dependencies and conflicts of software packages.

This part of the function is very important. Many puzzles can be solved here. exercise carefully. In fact, in most cases, simply press enter to accept the dselect suggestions.

4.2.4 other skills

You can use the I key to view the detailed information and brief information of the software package in a loop.
If the description of the software package is long, use the d key until all the introductions are completed.
Use the v key to change the display mode of the software package.
Use the o key to change the sorting method of the software package.

5. Install software packages

After selecting the software package to be installed, the following work is much easier. After the select Interface is returned to the main interface, the cursor is automatically moved to Install. Press the Enter key. Dselect often asks some questions when installing a software package to decide how to use the software package, so don't go away.

6. Configure the Software Package

In fact, during the installation process, the software package has been configured. In this step, complete the final configuration, ^_^.

7. delete unused software packages

Next, delete the software packages you selected to delete.

8. Exit. Complete!

That's easy! Right? Remember:

Do not be lazy.
Dselect can be used not only to install software packages, but also to delete and upgrade software packages. It is an all-around software package management tool.

Of course, if you are familiar with the software packages released by debian, you can also directly use dpkg and apt-get to manage the software packages. However, dselect is more friendly. I hope you will like the big manager of debian!

9. Postscript

I have been waiting for debian for a long time. I have never calmed down to take a closer look! I wrote this article on my way to using debian. errors are inevitable. I hope you can make a strong correction from the debian experts and heroes!

About the author

Su baochen (linuxman@263.net), graduated from Shandong Engineering College electrical technology in 1992, graduated from the Automation Department of Shanghai Jiao Tong University in 1997, obtained a master's degree, now works in Shandong Engineering College. Since I came into contact with Linux, I felt quite anxious and fell in love at first sight. Now I am mainly studying Linux, Java and its WEB applications. I am particularly familiar with the architecture and program design of Enhydra, and hope to have the opportunity to communicate with our colleagues.