The Evolution of a Programmer

這是一篇我在四、五年前看過的文章，大意是說在不同的階段，對同一個問題所用的解決方法會有所不同。
其實是很棒的文章；不只是最後那段幽默。
文中能用不同的方式來解同一個問題這點，我覺得就很發人省思了。

另外；我們可以從最未得到一個很明顯的結論。
越高階層的人，通常越少動腦思考…
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The Evolution of a Programmer

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
void main(void)
{
char *message[] = {"Hello ", "World"};
int i;

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

Seasoned professional
#include
#include

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();
importheader();
importheader();
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
#include
#include
#include
#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
#include
#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
#include
#include
#include
#include
#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
#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

Anonymous