【转自译言】资深程序员的成长道路

简介

你知道什么是所谓的编程高手吗？来看看一个编程高手的成长经历吧。
通过观察这些代码，身为程序员的你发现你所不理解的知识了吗？

高中时候

  10 PRINT "HELLO WORLD"
  20 END

大学第一年

  program Hello(input, output)
    begin
      writeln('Hello World')
    end.

高年级大学生

  (defun hello
    (print
      (cons 'Hello (list 'World))))

初级专家

  #include <stdio.h>
  void main(void)
  {
    char *message[] = {"Hello ", "World"};
    int i;

    for(i = 0; i < 2; ++i)
      printf("%s", message[i]);
    printf("\n");
  }

老练的专家

  #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);
  }

大师级程序员

  [
  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 = { /* 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);
  }

学徒级骇客

  #!/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;

老练的骇客

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

“逐鹿中原”级骇客

% echo "Hello, world."

初级管理员

  10 PRINT "HELLO WORLD"
  20 END

中级管理员

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

资深管理员

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

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