Software system dependency analysis

Software system dependency analysis

        The simplest understanding of dependencies is  Windows  Tips on the results of your game playing  directx  Version too low to run . And common prompts after running a program  mfc71.dll  Not found . There is also a software installation instruction that allows you to install it first  .net .
         Linux  Because his whole system is a collection of software developed by different development groups （ I don't know that Of Words are impossible to understand Linux The cause of dependency ）, Each software has different functions to provide and call . and  Linux  Because its software package composition can be very flexible , Some software packages are not required , Some software functions can be provided by many software . Therefore, the functional requirements of some software need “ Dependency relationship ” This description is used to describe the control .
Windows  It's also a problem , Just because the whole system is provided by Microsoft , Therefore, it can perform version interface functions , And convenient notification with multiple versions of function libraries and programs to provide functions , And forcibly provide some software that users do not need at all Windows programmatic “ Dependency relationship ”. The obvious dependencies are some ultra-high and compact  XP  The content removed will cause a lot of software not to run . so to speak , Simply remove  IE , You can make a lot of  Windows  The program loses its dependencies and cannot run .
       Linux  The package manager is designed to solve this problem . The software package manager determines whether and how dependencies are satisfied by analyzing the description information in the software package and the database of the current system installation （ That is, what software needs to be installed ）.