if(dst)
{
    free(dst);
    dst = NULL;
}

#include windows.h>
#include stdio.h>int to_utf8(char* psrc, char** ppdst)
{
    int ret,ret2;
    wchar_t* pws = NULL;
    char* putf = NULL;

    ret = MultiByteToWideChar(CP_ACP, 0, psrc, -1, NULL, 0);
    if(ret=0){
        *ppdst = NULL;
        return 0;
    }
    pws = (wchar_t*)malloc(ret*2);
    if(!pws){
        *ppdst = NULL;
        return 0;
    }
    MultiByteToWideChar(CP_ACP, 0, psrc, -1, pws, ret);
    ret2 = WideCharToMultiByte(CP_UTF8, 0, pws, -1, NULL, 0, NULL, NULL);
    if(ret2=0){
        free(pws);
        return 0;
    }
    putf = (char*)malloc(ret2);
    if(!putf){
        free(pws);
        return 0;
    }
    if(WideCharToMultiByte(CP_UTF8, 0, pws, ret, putf, ret2, NULL, NULL)){
        *ppdst = putf;
        free(pws);
        return 1;
    }else{
        free(pws);
        free(putf);
        *ppdst = NULL;
        return 0;
    }
}

int to_gb(char* psrc, char** ppdst)
{
    int ret, ret2;
    wchar_t* pws = NULL;
    char* pgb = NULL;
    ret = MultiByteToWideChar(CP_UTF8, 0, psrc, -1, NULL, 0);
    if(ret=0){
        *ppdst = NULL;
        return 0;
    }
    pws = (wchar_t*)malloc(ret*2);
    if(!pws){
        *ppdst = NULL;
        return 0;
    }
    MultiByteToWideChar(CP_UTF8, 0, psrc, -1, pws, ret);
    ret2 = WideCharToMultiByte(CP_ACP, 0, pws, -1, NULL, 0, NULL, NULL);
    if(ret2=0){
        free(pws);
        return 0;
    }
    pgb = (char*)malloc(ret2);
    if(!pgb){
        free(pws);
        *ppdst = NULL;
        return 0;
    }
    if(WideCharToMultiByte(CP_ACP, 0, pws, -1, pgb, ret2, NULL, NULL)){
        *ppdst = pgb;
        free(pws);
        return 1;
    }else{*ppdst = 0;
        free(pgb);
        free(pws);
        return 0;
    }
}