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Here are some examples of "Hello World" programs written by people at
different stages of their "careers".


High School/Jr.High
===================
10 PRINT "HELLO WORLD"
20 END



First year in College
=====================
program Hello(input, output)
begin
writeln('Hello World')
end.



Senior year in College
======================
(defun hello
(print
(cons 'Hello (list 'World))))



New professional
================
#include <stdio.h> void main(void)
{
char *message[] = {"Hello ", "World"}; int i;
for(i = 0; i < 2; ++i)
printf("%s", message[i]); printf("\n"); }



Seasoned professional
=====================
#include <iostream.h> #include <string.h>
class string
{
private:
int size; char *ptr;
public:
string() : size(0), ptr(new char('\0')) {}

string(const string &s) : size(s.size)
{
ptr = new char[size + 1]; strcpy(ptr, s.ptr); }

~string()
{
delete [] ptr; }

friend ostream &operator <<(ostream &, const string &); string &operator=(const char *); };
ostream &operator<<(ostream &stream, const string &s)
{
return(stream << s.ptr); }

string &string::operator=(const char *chrs)
{
if (this != &chrs)
{
delete [] ptr; size = strlen(chrs); ptr = new char[size + 1]; strcpy(ptr, chrs); }
return(*this); }

int main()
{
string str;
str = "Hello World"; cout << str << endl;
return(0); }



Master Programmer
=================
[
uuid(2573F8F4-CFEE-101A-9A9F-00AA00342820)
]
library LHello
{
// bring in the master library
importlib("actimp.tlb"); importlib("actexp.tlb");
// bring in my interfaces
#include "pshlo.idl"

[
uuid(2573F8F5-CFEE-101A-9A9F-00AA00342820)
]
cotype THello
{
interface IHello; interface IPersistFile; }; };
[
exe,
uuid(2573F890-CFEE-101A-9A9F-00AA00342820)
]
module CHelloLib
{

// some code related header files
importheader(<windows.h>); importheader(<ole2.h>); importheader(<except.hxx>); importheader("pshlo.h"); importheader("shlo.hxx"); importheader("mycls.hxx");
// needed typelibs
importlib("actimp.tlb"); importlib("actexp.tlb"); importlib("thlo.tlb");
[
uuid(2573F891-CFEE-101A-9A9F-00AA00342820),
aggregatable
]
coclass CHello
{
cotype THello; }; };

#include "ipfix.hxx"

extern HANDLE hEvent;
class CHello : public CHelloBase
{
public:
IPFIX(CLSID_CHello);
CHello(IUnknown *pUnk); ~CHello();
HRESULT __stdcall PrintSz(LPWSTR pwszString);
private:
static int cObjRef; };

#include <windows.h> #include <ole2.h> #include <stdio.h> #include <stdlib.h> #include "thlo.h"
#include "pshlo.h"
#include "shlo.hxx"
#include "mycls.hxx"

int CHello::cObjRef = 0;
CHello::CHello(IUnknown *pUnk) : CHelloBase(pUnk)
{
cObjRef++; return; }

HRESULT __stdcall CHello::PrintSz(LPWSTR pwszString)
{
printf("%ws\n", pwszString); return(ResultFromScode(S_OK)); }


CHello::~CHello(void)
{

// when the object count goes to zero, stop the server
cObjRef--; if( cObjRef == 0 )
PulseEvent(hEvent);
return; }

#include <windows.h> #include <ole2.h> #include "pshlo.h"
#include "shlo.hxx"
#include "mycls.hxx"

HANDLE hEvent;
int _cdecl main(
int argc,
char * argv[]
) {
ULONG ulRef; DWORD dwRegistration; CHelloCF *pCF = new CHelloCF();
hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
// Initialize the OLE libraries
CoInitializeEx(NULL, COINIT_MULTITHREADED);
CoRegisterClassObject(CLSID_CHello, pCF, CLSCTX_LOCAL_SERVER,
REGCLS_MULTIPLEUSE, &dwRegistration);
// wait on an event to stop
WaitForSingleObject(hEvent, INFINITE);
// revoke and release the class object
CoRevokeClassObject(dwRegistration); ulRef = pCF->Release();
// Tell OLE we are going away.
CoUninitialize();
return(0); }

extern CLSID CLSID_CHello; extern UUID LIBID_CHelloLib;
CLSID CLSID_CHello = { /* 2573F891-CFEE-101A-9A9F-00AA00342820 */
0x2573F891,
0xCFEE,
0x101A,
{ 0x9A, 0x9F, 0x00, 0xAA, 0x00, 0x34, 0x28, 0x20 }
};
UUID LIBID_CHelloLib = { /* 2573F890-CFEE-101A-9A9F-00AA00342820 */
0x2573F890,
0xCFEE,
0x101A,
{ 0x9A, 0x9F, 0x00, 0xAA, 0x00, 0x34, 0x28, 0x20 }
};
#include <windows.h> #include <ole2.h> #include <stdlib.h> #include <string.h> #include <stdio.h> #include "pshlo.h"
#include "shlo.hxx"
#include "clsid.h"

int _cdecl main(
int argc,
char * argv[]
) {
HRESULT hRslt; IHello *pHello; ULONG ulCnt; IMoniker * pmk; WCHAR wcsT[_MAX_PATH]; WCHAR wcsPath[2 * _MAX_PATH];
// get object path
wcsPath[0] = '\0'; wcsT[0] = '\0'; if( argc 1) {
mbstowcs(wcsPath, argv[1], strlen(argv[1]) + 1); wcsupr(wcsPath); }
else {
fprintf(stderr, "Object path must be specified\n"); return(1); }

// get print string
if(argc 2)
mbstowcs(wcsT, argv[2], strlen(argv[2]) + 1); else
wcscpy(wcsT, L"Hello World");
printf("Linking to object %ws\n", wcsPath); printf("Text String %ws\n", wcsT);
// Initialize the OLE libraries
hRslt = CoInitializeEx(NULL, COINIT_MULTITHREADED);
if(SUCCEEDED(hRslt)) {


hRslt = CreateFileMoniker(wcsPath, &pmk); if(SUCCEEDED(hRslt))
hRslt = BindMoniker(pmk, 0, IID_IHello, (void **)&pHello);
if(SUCCEEDED(hRslt)) {

// print a string out
pHello->PrintSz(wcsT);
Sleep(2000); ulCnt = pHello->Release(); }
else
printf("Failure to connect, status: %lx", hRslt);
// Tell OLE we are going away.
CoUninitialize(); }

return(0); }



Apprentice Hacker
===================
#!/usr/local/bin/perl
$msg="Hello, world.\n"; if ($#ARGV >= 0) {
while(defined($arg=shift(@ARGV))) {
$outfilename = $arg; open(FILE, ">" . $outfilename) || die "Can't write $arg: $!\n"; print (FILE $msg); close(FILE) || die "Can't close $arg: $!\n"; }
} else {
print ($msg); }
1;


Experienced Hacker
==================
#include <stdio.h> #define S "Hello, World\n"
main(){exit(printf(S) == strlen(S) ? 0 : 1);}



Seasoned Hacker
===============
% cc -o a.out ~/src/misc/hw/hw.c
% a.out



Guru Hacker
===========
% cat
Hello, world.
^D



New Manager
===========
10 PRINT "HELLO WORLD"
20 END



Middle Manager
==============
mail -s "Hello, world." bob@b12
Bob, could you please write me a program that prints "Hello,
world."?
I need it by tomorrow.
^D



Senior Manager
==============
% zmail jim
I need a "Hello, world." program by this afternoon.



Chief Executive
===============
% letter
letter: Command not found.
% mail
To: ^X ^F ^C
% help mail
help: Command not found.
% damn!
!: Event unrecognized
% logout

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