What should Linux/Unix 'make install' consist of?

Question

I've written a C++ program (command line, portable code) and I'm trying to release a Linux version at the same time as the Windows version. I've written a makefile as follows:

ayane: *.cpp *.h
    g++ -Wno-write-strings -oayane *.cpp

Straightforward enough so far; but I'm given to understand it's customary to have a second step, make install. So when I put the install: target in the makefile... what command should be associated with it? (If possible I'd prefer it to work on all Unix systems as well as Linux.)

Answer 1

make install is usually the step that "installs" the binary into the correct place.

For example, when compiling Vim, make install may place it in /usr/local/bin

Not all Makefiles have a make install

Answer 2

In the simplest case you just copy the newly created executable into the /usr/local/bin path. Of course, it's usually more complicated than that.

Notice that most of these operations require special rights, which is why make install is usually invoked using sudo.

Answer 3

Installation

A less trivial installer will copy several things into place, first insuring that the appropriate paths exists (using mkdir -p or similar). Typically something like this:

• the executable goes in $INSTALL_PATH/bin
• any libraries built for external consumption go in $INSTALL_PATH/lib or $INSTALL_PATH/lib/yourappname
• man pages go in $INSTALL_PATH/share/man/man1 and possibly other sections if appropriate
• other docs go in $INSTALL_PATH/share/yourappname
• default configuration files go in $INSTALL_PATH/etc/yourappname
• headers for other to link against go in $INSTALL_PATH/include/yourappname

Installation path

The INSTALL_PATH is an input to the build system, and usually defaults to /usr/local. This gives your user the flexibility to install under their $HOME without needing elevated permission.

In the simplest case just use

INSTALL_PATH?=/usr/local

at the top of the makefile. Then the user can override it by setting an environment variable in their shell.

Deinstallation

You also occasionally see make installs that build a manifest to help with de-installation. The manifest can even be written as a script to do the work.

Another approach is just to have a make uninstall that looks for the things make install places, and removes them if they exist.