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How to understand the Linux package dependence problem, I believe that many inexperienced people do not know what to do. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

Linux package dependencies are troublesome for many people who use Linux. When installing the Linux system, you do not choose to install all the software packages. After the installation, if you install the software again, you may encounter some dependency problems, such as some error messages when installing some programming packages. Said it needed the support of some other software packages.

What should I do if I encounter such Linux package dependencies? Before I talk about this specific solution, let me tell you about the circumstances in which software package dependencies are prone to occur.

First, when the operating system is installed, not all the software packages are selected. Most of the time, for security or other reasons, Linux system administrators often do not choose to install all the packages. Instead, install some software packages necessary to run the related services. But sometimes the system administrator may not know which packages must be installed, otherwise some subsequent services will not be able to start; those packages are optional. Because it is difficult to figure out these contents at once when the system is installed, this problem is easy to occur when some other software packages are deployed after the installation of the Linux system.

Second, when adding some other application services to the Linux server, it is easy to have similar problems. If there is a time when an enterprise needs to use an Oracle database, I install the Oracle database on the original file server. However, installing Oracle server on Linux operating system is a headache, and a lot of software packages need to be installed. When I first deployed the Linux file server, I didn't know that I needed to install the Oracle database later, so many software packages were not installed. And later found that many software packages are not actually in the Linux installation disk, need to go to the Internet. Therefore, if you want to add some application services to the previously deployed Linux server, it is easy to have the dependency problem of this software package.

In fact, it is not simple to solve the problem of Linux package dependence, and it is not complex to say that it is complex. I have summarized a few methods below, which you can use for reference if you need to.

First, look for it in the installation CD according to the error message.

If you encounter software dependency problems when installing a software package, the system usually prompts you for relevant information. Such as the prompt "libgd.so.1.8 is needey by php-4.2.2-17" and so on. This means that when installing the PHP program, you need to install the libgd.so package first. When you encounter this problem, I suggest that the system administrator can use this prompt to find out if this package is available from the installation disk of the Linux system.

As shown in the figure above, a large number of software packages are stored in the RPMS directory on the Linux installation disk. In general, common software packages such as libgd.so above can be found on this CD. So according to the error message of the system, the system administrator can know which software package should be installed before installing a certain software. Then find the package from the system CD and install it. It is also important to note that to the RedHat operating system, if the CD installation disk is used, it may have many CDs. These packages are often not stored on a CD CD. But to be sure, there will be a directory called RPMS under every CD. When the system administrator does not know which disk a software package is stored in, he can look for it one by one. Although it is a bit troublesome, it will be rewarded in most cases.

However, there is a limitation if this method is adopted. Large-scale applications such as Oracle are not suitable. Because it takes time to install such large-scale software itself. If you wait until the installation fails and then install the package according to the error prompt, repeating it over and over again will waste a lot of time and cause the system to produce a lot of junk files. For this reason, unless it is a small software package, it will be done according to the method I will introduce below to save the time of software installation.

Second, refer to the official documents.

Usually, the official documentation of some software will indicate which software packages are required to install them. For example, when installing Oracle databases, you must install a number of software packages. Which packages need to be installed will be explained in detail on Oracle's official website. When I install the Oracle database, I install this description to verify that these packages are installed on the Linux system. If it is not installed, install it right away. At this time, the Linux system administrators should not take a chance, there will be no big problem if they are not installed. This is a big mistake. The software packages recommended on the official website of Oracle must be installed thoroughly before the Oracle database system is installed. Otherwise, light will lead to database installation failure, serious cases will lead to subsequent database operation instability.

In fact, not only the Oracle database system, but also some other applications have similar requirements for Linux systems. They require that certain packages must be installed on the Linux system before installing their applications, otherwise the installation will fail. So I advise all Linux system administrators to look for similar documents on the official website before installing these software, and then check against the contents of the documents to verify whether these software packages are installed on the Linux system. In this way, the problem of package dependencies can be avoided. In addition, a lot of useful value can be found on the Internet. Some Linux system administrators who have installed this software will list the package dependencies encountered by the system during installation and specify which packages need to be installed first. Although these online documents may not be as professional as official documents. But it also has great reference value for us.

Third, inquire from the professional network.

In order to install some packages correctly, you need to install some files. However, sometimes the system administrator may not be able to determine which software packages will have these files at the prompt of the system. This problem is often encountered, especially for some less commonly used software packages or software packages that are contacted by system administrators. At this point, the system administrator can inquire on some professional websites. Here I would like to introduce you to a very good website, namely http://rpmfind.net. The system administrator only needs to enter the desired file name, such as libgd.so, where the site is searched, and the search results will show which package needs to be installed to have the file. Once you find the name of the package, you only need to download the package from CD or network to install it. Of course, when installing these packages, you may also encounter other package dependency issues. If you install the php package, you need the libgd.so file, which belongs to the gb package. However, when installing the gb package, it may be dependent on other packages and other packages need to be installed. At this point, the system administrator needs to be patient and solve them one by one in order.

It can be seen that in most cases, when you encounter the problem of package dependency, the file name provided by the operating system will be directly related to the package name. It is possible that the name of the file is the name of the package. But sometimes the name of the file is very different from the name of the software package. At this point, most system administrators may not be able to find the corresponding software package based on the file name alone. At this point, we need to use some of the professional websites mentioned above to query the name of the software package.

In addition, I have a little suggestion. After the system administrator installs a certain software, if there is a dependency between the software packages, then * can take the book or record it by other means. Because in the future work is likely to need to install these software. In that case, you won't have to go to so much trouble in the next installation. You can install the required software packages directly against previous notes. After all, it is not honorable to fall in the same place many times.

These are my tricks for solving the Linux package dependency problem.

After reading the above, have you mastered how to understand the problem of Linux package dependency? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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