
	Welcome to the introduction of C.


Please compile and run the following hello world programs.


Notice that the following files has two versions.
one of C and one of I.

	- the c versions - Source Code in C
	- the i versions - Pre-processed Source Code in C (for Linux Platform)

when a C file is pre-processed, the remarks - // , /* ... */
and #include , #define (and other #symbols) are removed.



	Notice that main returns a value which can be used by the OS.


 - for windows, create the "HelloWorld.exe", 
	run it in cmd (command line)
	and than write the following command:

		echo %ERRORLEVEL%

 - for linux, create the execute "HelloWorld" (you can use gcc <file.c>), 
	run it in shell
	and than write the following command:

		echo $?


You will see the return value accepted by the command line.

This can be used in scripts to determine 
whether the code has finished successfully or not.

By default, 0 value is success, 
all the rest are the error numbers of the program.


Good luck.