Primer paso de programación «Hello world»

(Nota para los que no son programadores: «Hello World» es el nombre del primer programa que se aprende a realizar cuando comienzas a estudiar un lenguaje de programación.y consiste en imprimir una línea en la pantalla que ponga eso «Hola mundo»)

—————
Programas *Hello World* diseñados según la categoría del programador.

Primaria
===================

10 PRINT «HELLO WORLD»

20 END

Secundaria
=====================

program Hello(input, output)

begin

writeln(‘Hello World’)

end.

Bachiller
======================

(defun hello

(print

(cons ‘Hello (list ‘World))))

Profesional
================

#include <stdio.h>

void main(void)

{

char *message[] = {«Hello «, «World»};

int i;

for(i = 0; i < 2; ++i)

printf(«%s», message[i]);

printf(«n»);

}

Profesional avanzado
=====================

#include <iostream.h>

#include <string.h>

class string

{

private:

int size;

char *ptr;

public:

string() : size(0), ptr(new char(»)) {}

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);

}

Programador con experiencia
===========================

[

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(«%wsn», 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] = »;

wcsT[0] = »;

if( argc 1) {

mbstowcs(wcsPath, argv[1], strlen(argv[1]) + 1);

wcsupr(wcsPath);

}

else {

fprintf(stderr, «Object path must be specifiedn»);

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 %wsn», wcsPath);

printf(«Text String %wsn», 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);

}

Aprendiz de 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;

Hacker con experiencia
======================

#include <stdio.h>

#define S «Hello, Worldn»

main(){exit(printf(S) == strlen(S) ? 0 : 1);}

Hacker avanzado
===================

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

% a.out

Guru Hacker
===================

% cat

Hello, world.

^D

Jefe
===================

10 PRINT «HELLO WORLD»

20 END

Jefe intemedio
===================

mail -s «Hello, world.» bob@b12

Antonio, ¿ Me puedes hacer un programa que imprima  «Hello, world.»?

Lo necesito para mañana.

^D

Director gerente
===================

% zmail jim

Necesito el  programa «Hello, world.» para esta tarde.

Director Ejecutivo
===================

% letter

letter: Command not found.

% mail

To: ^X ^F ^C

% help mail

help: Command not found.

% damn!

!: Event unrecognized

% logout

—————–

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