UTF-8、GBK等格式互相转换 [Windows/Linux 通用]

#ifdef WIN32
#include <windows.h>
#endif#ifdef OS_UNIX
#include <iconv.h>
#endif#if defined(WIN32)
void convert_encoding(const char *input, int from_codepage, int to_codepage, char *output)
{int wlen = MultiByteToWideChar(from_codepage, 0, input, -1, NULL, 0);if (0 == wlen)return;wchar_t *wbuf = (wchar_t *)malloc((wlen + 1) * sizeof(wchar_t));MultiByteToWideChar(from_codepage, 0, input, -1, wbuf, wlen);int len = WideCharToMultiByte(to_codepage, 0, wbuf, -1, NULL, 0, NULL, NULL);if (0 == len){free(wbuf);return;}WideCharToMultiByte(to_codepage, 0, wbuf, -1, output, len, NULL, NULL);free(wbuf);
}
#else
void convert_encoding(const char *input, const char *from_encoding, const char *to_encoding, char *output)
{iconv_t cd = iconv_open(to_encoding, from_encoding);if (cd == (iconv_t)-1)return;size_t in_len = strlen(input);size_t out_len = in_len * 2; // 输出长度最多为输入长度的2倍char *in_ptr = input, *out_ptr = output;size_t ret = iconv(cd, &in_ptr, &in_len, &out_ptr, &out_len);if (ret == (size_t)-1){iconv_close(cd);return; // 转换失败}*out_ptr = '\0'; // 添加字符串结尾iconv_close(cd);
}
#endif// 用法例：// 从共享内存取到UTF-8格式的字符串res，转换为GBK格式字符串tmpstr
#ifdef WIN32convert_encoding(res, CP_UTF8, CP_ACP, tmpstr);
#elseconvert_encoding(res, "UTF-8", "GBK", tmpstr);
#endif