从Hello World 看一个IT人的成长

High School/Jr.High
    念高中時的程式碼
 
      10 PRINT "HELLO WORLD"
      20 END
 
 
 
    First year in College
    在大學的第一年的程式碼
 
      program Hello(input, output)
        begin
          writeln('Hello World')
        end.
 
 
 
    Senior year in College
    在大學的高年級的程式碼
 
      (defun hello
        (print
          (cons 'Hello (list 'World))))
 
 
 
    New professional
    成為公司的新人員
 
      #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
    進入公司有兩年了
 
      #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
    升成軟體部經理那年寫的程式
 
      [
      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
    駭客學徒階段
 
      #!/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
    有經驗經驗的駭客
 
      #include <stdio.h>
      #define S "Hello, World\n"
      main(){exit(printf(S) == strlen(S) ? 0 : 1);}
 
 
 
 
 
    Seasoned Hacker
    有經驗豐富的駭客
      % cc -o a.out ~/src/misc/hw/hw.c
      % a.out
 
 
 
 
 
    Guru Hacker
    成為駭客界的精神導師
 
      % echo "Hello, world."