Compiling C++ programs with g++

gistfile1.txt

Compiling C++ programs with g++
-------------------------------

The base command for the Gnu C compiler is "gcc"
The base command for the Gnu C++ compiler is "g++"

Single File Programs
--------------------

To compile a program that is in a single file, the easiest compilation
uses the command format:

   g++ <filename>

(where the filename ends with ".cpp").

Example:
	g++ prog1.cpp

This command will create an executable program called "a.out" (the default
executable target name when one is not specified).

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Multiple File Programs
----------------------

To invoke the Compile stage, which translates source code (.cpp files)
into object code (.o files), use the -c flag.  Format:

  g++ -c <filename>

When the -c option is NOT used, the compiler will expect the command to 
give everything necessary to compile AND link -- to make the executable.

To name a target (something other than the default filename, use the -o flag.  
Format:

  g++ -o <target_name> <remainder of command>

A few examples:

  g++ -o yadda.o -c fraction.cpp

This command invokes just the compile stage on fraction.cpp, but names the 
object code file "yadda.o" (instead of the default "fraction.o").

  g++ -o bob.exe circle.o main.o

This command links the two object code files ("circle.o" and "main.o") 
into an executable, called "bob.exe" (instead of the default "a.out").

  g++ -o myProgram thing.cpp main.cpp

This command compiles and links (since -c not used) the code files 
"thing.cpp" and "main.cpp" together into the executable program called 
"myProgram".

There are other command formats, flags,  and shortcuts, which are not
listed here.  The above commands are sufficient for basic compilation
needs.
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Example:
--------

The following example is the step by step compilation of the files for
the fraction class example.

  To compile the cpp files into object code:
					g++ -c frac.cpp
					g++ -c main.cpp

  Now, the object code files frac.o and main.o have been created.

  To link the object code:		g++ -o frac frac.o main.o

  This creates the executable "frac"

  run the program:			frac