Hello World: The Evolution of a Programmer
High School / Junior High School

10    PRINT "HELLO WORLD"
20    END

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First Year in College

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

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Senior Year in College

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

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New Professional

#include <stdio.h>

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

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

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Seasoned Professional

#include <iostream>
#include <cstring>

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

[
uuid = (2573F8F4-CFEE-101A-9A9F-00AA00342820)
]

library LHello {
    // bring in the master library
    importlib("actimport.tlb");
    importlib("actexport.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("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 "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 "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
    CoInitiali, 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 "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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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;

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Experienced Hacker

#define S "Hello, World\n"
main() { exit(printf(S) == strlen(S) ? 0 : 1); }

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Seasoned Hacker

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

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Guru Hacker

% cat
Hello, world.
^D

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AXE Assembly Programmer

LL0:
        .seg    "data"
        .seg    "text"
        .proc    04
        .global  _main
_main:
        !#PROLOGUE# 0
        sethi   %hi(LF26),%g1
        add     %g1,%lo(LF26),%g1
        save    %sp,%g1,%sp
        !#PROLOGUE# 1
        .seg    "data1"
L30:
        .ascii  "Hello, World\012\0"
        .seg    "text"
        .seg    "data1"
L32:
        .ascii  "Hello, World\012\0"
        .seg    "text"
        set     L32, %o0
        call    _strlen, 1
        nop
        mov     %o0, %i5
        set     L30, %o0
        call    _printf, 1
        nop
        cmp     %o0, %i5
        bne     L2000000
        nop
        mov     0, %o0
        b       L2000001
        nop
L2000000:
        mov     0x1, %o0
L2000001:
        call    _exit, 1
        nop
LE26:
        ret
        restore
        LF26 = -96
        LP26 = 96
        LST26 = 96
        LT26 = 96
        .seg    "data"

0000000 0103 0107 0000 0060 0000 0020 0000 0000
0000020 0000 0030 0000 0000 0000 0054 0000 0000
0000040 033f ffff 8200 63a0 9de3 8001 1100 0000
0000060 9012 2000 4000 0000 0100 0000 ba10 0008
0000100 1100 0000 9012 2000 4000 0000 0100 ba10
0000100 1100 0000 9012 2000 4000 0000 0100 0000
0000120 80a2 001d 1280 0005 0100 0000 9010 2000
0000140 1080 0003 0100 0000 9010 2001 4000 0000
0000160 0100 0000 81c7 e008 81e8 0000 0000 0000
0000200 4865 6c6c 6f2c 2057 6f72 6c64 0a00 4865
0000220 6c6c 6f2c 2057 6f72 6c64 0a00 0000 0000
0000240 0000 000c 0000 0608 0000 006e 0000 0010
0000260 0000 060b 0000 006e 0000 0014 0000 0286
0000300 ffff ffec 0000 0020 0000 0608 0000 0060
0000320 0000 0024 0000 060b 0000 0060 0000 0028
0000340 0000 0186 ffff ffd8 0000 004c 0000 0386
0000360 ffff ffb4 0000 0004 0500 0000 0000 0000
0000400 0000 000a 0100 0000 0000 0000 0000 0012
0000420 0100 0000 0000 0000 0000 001a 0100 0000
0000440 0000 0000 0000 0020 5f6d 6169 6e00 5f70
0000460 7269 6e74 6600 5f73 7472 6c65 6e00 5f65
0000500 7869 7400
0000504

% axe_generate -f system.uhdl
Application 'Exchange' generated
2324042350000000 source code lines
No Errors detected.
Hardware retrieval...done OK
Certification Test...done OK
Packing..............done OK
Delivery.............done OK
Application 'Exchange' delivered to customer
23456000 bytes/sec.
End processing, 2345 seconds.

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New Manager

10 PRINT "Hello World"
20 END

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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

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Senior Manager

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

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Chief Executive

$ message
message: not found
$ pm
pm: not found
$ letter
letter: not found
$ mail
To: ^X ^F ^C
> help mail
help: not found
> what
what: not found
> need help
need: not found
> damn!
!: Event unrecognized
> exit
exit: unknown
> quit
$ logout

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