Dll Test

#include "windows.h"

extern "C" __declspec(dllexport) int  StrLength(const char* str);
extern "C" __declspec(dllexport) void StrConcat(char* str, const char* str1);
extern "C" __declspec(dllexport) void StrCopy(char* str, const char* str1);
extern "C" __declspec(dllexport) void StrReverse(char* str);

BOOL APIENTRY DllMain(_In_ void * _HDllHandle, _In_ unsigned _Reason, _In_opt_ void * _Reserved)
{
    return TRUE;
}

int StrLength(const char* str)
{
    DWORD i = 0;
    while(*str++) i++;
    return i;
}

void StrConcat(char* str, const char* str1)
{
    for(int i=StrLength(str)-1, j=0; i < StrLength(str) + StrLength(str1) - 1; i++, j++)
    {
        *(str+i) = *(str1+j);
    }
}

void StrCopy(char* str, const char* str1)
{
    while(*str++ = *str1++);
}

void StrReverse(char* str)
{
    int i = StrLength(str);
    for(int j = 0; j < i / 2; j++, i--)
    {
        char ch = str[i];
        str[i] = str[j];
        str[j] = ch;
    }
}