2.2.1 Basic Installation

The most common installation procedure looks as follows.

~ % tar zxf amhello-1.0.tar.gz
~ % cd amhello-1.0
~/amhello-1.0 % ./configure
…
config.status: creating Makefile
config.status: creating src/Makefile
…
~/amhello-1.0 % make
…
~/amhello-1.0 % make check
…
~/amhello-1.0 % su
Password:
/home/adl/amhello-1.0 # make install
…
/home/adl/amhello-1.0 # exit
~/amhello-1.0 % make installcheck
…

The user first unpacks the package. Here, and in the following examples, we will use the non-portable tar zxf command for simplicity. On a system without GNU tar installed, this command should read gunzip -c amhello-1.0.tar.gz | tar xf -.

The user then enters the newly created directory to run the ‘configure’ script. This script probes the system for various features, and finally creates the ‘Makefile’s. In this toy example there are only two ‘Makefile’s, but in real-world projects, there may be many more, usually one ‘Makefile’ per directory.

It is now possible to run make. This will construct all the programs, libraries, and scripts that need to be constructed for the package. In our example, this compiles the ‘hello’ program. All files are constructed in place, in the source tree; we will see later how this can be changed.

make check causes the package's tests to be run. This step is not mandatory, but it is often good to make sure the programs that have been built behave as they should, before you decide to install them. Our example does not contain any tests, so running make check is a no-op.

After everything has been built, and maybe tested, it is time to install it on the system. That means copying the programs, libraries, header files, scripts, and other data files from the source directory to their final destination on the system. The command make install will do that. However, by default everything will be installed in subdirectories of ‘/usr/local’: binaries will go into ‘/usr/local/bin’, libraries will end up in ‘/usr/local/lib’, etc. This destination is usually not writable by any user, so we assume that we have to become root before we can run make install. In our example, running make install will copy the program ‘hello’ into ‘/usr/local/bin’ and ‘README’ into ‘/usr/local/share/doc/amhello’.

A last and optional step is to run make installcheck. This command may run tests on the installed files. make check tests the files in the source tree, while make installcheck tests their installed copies. The tests run by the latter can be different from those run by the former. For instance, there are tests that cannot be run in the source tree. Conversely, some packages are set up so that make installcheck will run the very same tests as make check, only on different files (non-installed vs. installed). It can make a difference, for instance when the source tree's layout is different from that of the installation. Furthermore it may help to diagnose an incomplete installation.

Presently most packages do not have any installcheck tests because the existence of installcheck is little known, and its usefulness is neglected. Our little toy package is no better: make installcheck does nothing.