Complex sentence: For instance, in Unix sytems the make command is used to compile new or modified code without the need to recompile unchanged code-the make command uses the clock of the machine it runs on to determine which source files need to be recompiled.
Split into simpler sentences: For instance, in Unix sytems the make command is used to compile new or modified code without the need to recompile unchanged code. The make command uses the clock of the machine it runs on to determine which source files need to be recompiled.