In the previous example, the compiler automatically generates the loader object files (file1.o, file2.o and file3.o) and then invokes the system linker to create the executable program for the file prgrm.
After compilation, the object files (file1.o, file2.o,and file3.o) remain. This convention permits you to easily relink and recompile your files.
If only one source file is compiled and a program is linked in the same operation, the corresponding .o file is deleted automatically. To preserve all .o files, do not compile and link in the same operation unless more than one source file gets compiled.
If the compilation fails, you will receive a message for each error. No .o files are generated for those source files with errors, and no executable program is written.