What is $@ in Makefile?

A simple makefile consists of “rules” with the following shape: target … : prerequisites … recipe … … A target is usually the name of a file that is generated by a program ; examples of targets are executable or object files. A target can also be the name of an action to carry out, such as ‘ clean ‘ (see Phony Targets).

Dynamic libraries are a collection of object files which are referenced at build time to give the executable information how they will eventually be used, but they aren’t used until run time . In other words, these objects are dynamically linked into executables that use them.

$@ is the name of the target being generated , and $< the first prerequisite (usually a source file). You can find a list of all these special variables in the GNU Make manual.

In computing, rpath designates the run-time search path hard-coded in an executable file or library . … The rpath of an executable or shared library is an optional entry in the . dynamic section of the ELF executable or shared libraries, with the type DT_RPATH , called the DT_RPATH attribute.

The make-specific variables (the ones in capital letters) follow a name convention such that: CC refers to the compiler (gcc in this case); CFLAGS contains compiler directives/options; and LDFLAGS is a list of link (or “load”) directives (here, instructions to link with the C math library).

First, create a makefile in the directory where you want your dynamic library to be created, and declare a phony target all whose single prerequisite is the dynamic library. Next, declare your dynamic library target.

There are four steps: