Is it usually necessary to do make and then make install?

Question

This is something that has always bugged me. It seems like I always see build instructions for building and then installing something saying to do this:

make
sudo make install

Is there really any reason to call make? Doesn't sudo make install implicitly call make?

Answer 1

Technically, there is no reason why not - this really is based on how the makefile was set up. It is all designed around dependencies. If the 'install' target is made dependent on the rest of the product, then it would implicitly build the product as you are thinking.

The reason they are separated out is that you are usually going to do a 'make' as the unprivileged developer, and do the 'make install' with elevated privs. Usually you don't want to mix those actions.

Answer 2

The 2 commands do different things.

make - this reads the makefile for instructions on how to compile the sources. It builds the program and the end result is your binaries.

make install - this reads the makefile for the target install directory, and places the files created by make into their appropriate directories.