Understanding Linux Installation Software

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This tutorial are aimed at those who has just started using Linux. Generally when users from the Windows background enter the Linux Scene,they is totally stumped by the software Installati On method. They were used to the luxury of double clicking on a single file and getting their software installed. But now they has to type cryptic commands to do the same.

Though the installation instructions tell them what does, they has no ideaWhat those steps actually do. This article shall explain the basics of software installation. After reading the article you would feel more at home when installing your next software.

Generally beginners tend to search desperately for RPMs since installing RPMs are a real simple task. But this article doesn ' t talk about RPMs. It deals with the softwares so you generally get in the zipped formats as tarballs.


Details:

Generally would get Linux software in the Tarball format (. tgz) This file have to is uncompressed into any directory us ing tar command. Download a new tarball by the name game.tgz and then you would has to type the following command

$ tar xfvz game.tgz

This would create a directory within the current directory and unzip all the files within that new directory. Once This was complete the installation instructions ask for Execute the 3 (now famous) Commands:configure, Make & Make install. Most of the users does this and successfully install their softwares. But the very most of the newbies has no idea about this really does. The rest of the article shall explain the meaning of these 3 commands

Each software comes with a few files which is solely for the purpose of installation sake. One of them is the Configure script. The user have to run the following command at the prompt

$./configure

The above command makes the shell run the script named 'Configure' which exists in the current directory. The Configure script basically consists of many lines which is used to check some details about the machine on which the Software is going to be installed. This script checks for lots the dependencies on your system. For the particular software-to-work properly, it could be requiring a lot of things-be existing on your machine already. When you run the Configure script you would see a lot of output on the screens, each being some sort of question and a res Pective yes/no as the reply. If any of the major requirements is missing on your system, the Configure script would exit and your cannot proceed with T He installation, until you get those required things.

The main job of the Configure script is to create a 'Makefile‘ . This was a very important file for the installation process. Depending on the results of the tests (checks), the Configure script performed it would write down the various steps T Hat need to is taken (while compiling the software) in the file named Makefile.

If you get no errors and the Configure script runs successfully (if there was any error the last few lines of the output wo Uld glaringly be stating the error) then you can proceed with the next command which is

$ make

‘ Make' is actually a utility which exists on almost all Unix systems. For make utility to work it requires a file named Makefile in the same directory in which you run make. As we have seen the Configure script ' s main job is to create a file named Makefile to is used with make utility. (Sometimes the Makefile is named as Makefile also)

Make would use the directions present in the Makefile and proceed with the installation. The Makefile indicates the sequence, that's Linux must follow to build various components/sub-programs of your software. The sequence depends on the same the software is designed as well as many other factors.

The Makefile actually have a lot of labels (sort of names for different sections). Hence depending on what needs to being done the control would being passed to the different sections within the Makefile Or it I s possible that at the end of one of the sections there is a command to go to some next section.

Basically the Make utility compiles all your program code and creates the executables. For particular sections of the program to complete might require some and other part of the code already ready, this is what th E Makefile does. It sets the sequence for the events so this your program does not complain about missing dependencies.

One of the labels present in the Makefile happens to be named ' install '.

If make ran successfully then you are almost do with the installation. The last step remains which is

$ make Install

As indicated before make uses the file named Makefile in the same directory. When you run make without any parameters, the instruction in the Makefile begin executing from the start and as per the RU Les defined within the Makefile (particular sections of the code may execute after one another: Thats why labels is used. to another). If you have run make with install as the parameter, the make utility searches for a label named install within the Ma Kefile, and executes only that section of the the Makefile.

The install section happens to is only a part where the executables and other required files created during the last step (i.e. make) is copied into the required final directories on your machine. e.g. the executable that the user runs is copied to The/usr/local/bin so, all users is able to run the software. Similarly all of the other files is also copied to the standard directories in Linux. Remember that's when you ran make, all the executables were created in the temporary directory where you had unzipped your O Riginal Tarball. If you run make install, these executables is copied to the final directories.

thats it!! Now the installation process must is clear to you. You surely'll feel more at home if you begin your next software installation.

Understanding Linux Installation Software