Changes

* The source code for large projects is divided into many source files for manageability. The dependencies between these files can become complex. When developing or debugging the software, it is often necessary to make changes in one or a small number of files, and it may not be necessary to rebuild the entire project from scratch. The [[Make_and_Makefiles|<code>make</code>]] utility is used to script a build and to enable rapid partial rebuilds after a change to source code files(see [[Make and Makefiles]]). * Many open source projects distribute code as a source archive ("tarball") which usually decompresses to a subdirectory '''packageName-version''' (e.g. foolib-1.5.29). This will typically contain a script which configures the Makefile (<code>configure</code> if using GNU Autotools). After running this script, a Makefile will be available, which can be used to build the software. However, some projects use an alternative configuration tool instead of GNU Autotools, and some may use an alternate build system instead of make.* To eliminate this variation, most Linux distributions use a '''package''' system, which standardizes the build process and which produces installable package files which can be used to reliably install software into standard locations with automatic dependency resolution, package tracking via a database, and simple updating capability. For example, Fedora, Red Hat Enterprise Linux, CentOS, SuSE, and OpenSuSE all use the RPM package system, in which source code is bundled with a build recipe in a "Source RPM" (SRPM), which can be built with a single command into a binary package (RPM). The RPMs can then be downloaded, have dependencies and conflicts resolved, and installed with a single command such as <code>dnf</code>. The fact that the SRPM can be built into an installable RPM through an automated process enables and simplifies automated build systems, mass rebuilds, and architecture-specific builds.