Finish 3rd example

execEx/02/SConstruct

@@ -0,0 +1,73 @@
+
+Help("""
+
+  This is the second scons example. In this example we explore more options in
+  scons. Once you start doing anything useful with scons other than showing
+  how simple scons works, you will have to create an environment to have more 
+  control on the build.
+  
+  One can "Dump()" the environment to see all the underlying details. We can 
+  also compare between Linux and windows environments.
+
+>> ls
+foo.cpp  foo.hpp  main.cpp  SConstruct
+
+>> scons
+scons: Reading SConscript files ...
+------------------>starting
+------------------>ending
+scons: done reading SConscript files.
+scons: Building targets ...
+g++ -o foo.o -c foo.cpp
+g++ -o main.o -c main.cpp
+g++ -o helloworld main.o foo.o
+scons: done building targets.
+
+
+>> ls -a
+total 68
+drwxr-xr-x 2 brgirgis users   154 Sep 26 23:04 ./
+drwxr-xr-x 5 brgirgis users    36 Sep 26 22:44 ../
+-rw-r--r-- 1 brgirgis users 21096 Sep 26 23:04 env.txt
+-rw-r--r-- 1 brgirgis users    48 Sep 26 22:42 foo.cpp
+-rw-r--r-- 1 brgirgis users   109 Sep 26 22:40 foo.hpp
+-rw-r--r-- 1 brgirgis users  1256 Sep 26 23:03 foo.o
+-rwxr-xr-x 1 brgirgis users 13288 Sep 26 23:03 helloworld*
+-rw-r--r-- 1 brgirgis users   117 Sep 26 22:41 main.cpp
+-rw-r--r-- 1 brgirgis users  2872 Sep 26 23:03 main.o
+-rw-r--r-- 1 brgirgis users  2441 Sep 26 23:04 .sconsign.dblite
+-rw-r--r-- 1 brgirgis users  1348 Sep 26 23:04 SConstruct
+
+
+>> scons --tree=all helloworld
+scons: Reading SConscript files ...
+------------------>starting
+------------------>ending
+scons: done reading SConscript files.
+scons: Building targets ...
+scons: `helloworld' is up to date.
++-helloworld
+  +-main.o
+  | +-main.cpp
+  | +-foo.hpp
+  | +-/usr/bin/g++
+  +-foo.o
+  | +-foo.cpp
+  | +-foo.hpp
+  | +-/usr/bin/g++
+  +-/usr/bin/g++
+scons: done building targets.
+
+
+""")
+
+print('------------------>starting')
+env = Environment()
+
+open('env.txt', 'w').write(env.Dump())
+
+env.Program(target='helloworld',
+            source=['main.cpp', 'foo.cpp'])
+
+print('------------------>ending')
+

execEx/02/foo.cpp

@@ -0,0 +1,8 @@
+
+#include "foo.hpp"
+
+int
+foo()
+{
+  return 32;
+}

execEx/02/foo.hpp

@@ -0,0 +1,6 @@
+#ifndef SRC_EXECEX_02_FOO_HPP_
+#define SRC_EXECEX_02_FOO_HPP_
+
+int foo();
+
+#endif  // SRC_EXECEX_02_FOO_HPP_

execEx/02/main.cpp

@@ -0,0 +1,12 @@
+
+#include "foo.hpp"
+
+#include <iostream>
+
+int
+main()
+{
+  std::cout << "foo = " << foo() << std::endl;
+
+  return 0;
+}