由”Hello World”看程序员的成长


中学阶段



10 PRINT "HELLO WORLD"

20 END

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大学一年级



program Hello(input, output)

begin

writeln('Hello World')

end.

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大学高年级



(defun hello

(print

(cons 'Hello (list 'World))))

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初级程序员



#include <stdio.h>

void main(void)

{

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

int i;



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

printf("%s", message[i]);

printf("\n");

}

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编程老鸟



#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 &amp;);

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 << end



return(0);

}

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编程高手



[

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);

}

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黑客初阶



#!/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;

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黑客有成



#include <stdio.h>

#define S "Hello, World\n"

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

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黑客高手



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

% a.out

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黑客大虾



% cat

Hello, world.

^D

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初级经理



10 PRINT "HELLO WORLD"

20 END

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中级经理



mail -s "Hello, world." bob@b12

Bob, could you please write me a program that prints "Hello, world."?

I need it by tomorrow.

^D

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高级经理



% zmail jim

I need a "Hello, world." program by this afternoon.

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首席执行官



% letter

letter: Command not found.

% mail

To: ^X ^F ^C

% help mail

help: Command not found.

% damn!

!: Event unrecognized

% logout

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