Наглядный пример эволюции программиста.

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;

 string() : size(0), ptr(new char[1]) { ptr[0] = 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
", 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 = {
 0x2573F891,
 0xCFEE,
 0x101A,
 { 0x9A, 0x9F, 0x00, 0xAA, 0x00, 0x34, 0x28, 0x20 }
 };

 UUID LIBID_CHelloLib = {
 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
% echo "Hello, world."
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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