字符集转换函数

int code_convert(char *from_charset,char *to_charset,char *inbuf,size_t inlen,char *outbuf, size_t outlen)
{
        iconv_t cd;
        char **pin = &inbuf;
        char **pout = &outbuf;

        cd = iconv_open(to_charset,from_charset);
        if (cd==0) return -1;
        memset(outbuf,0,outlen);
        if (iconv(cd,pin,&inlen,pout,&outlen)==-1) return -1;
        iconv_close(cd);
        return 0;
}

int u2g (char *inbuf, int inlen, char *outbuf, int outlen)
{
  return code_convert ("utf-8", "gb2312", inbuf, inlen, outbuf, outlen);
}

int g2u (char *inbuf, size_t inlen, char *outbuf, size_t outlen)
{
  return code_convert ("gb2312", "utf-8", inbuf, inlen, outbuf, outlen);
}