Linux下面的没有命名为 WideCharToMultiByte() 和 MultiByteToWideChar() 函数，WideCharToMultiByte，MultiByteToWideChar是windows下的函数，在linux下也有类似的两个函数：

mbstowcs()
wcstombs()

值得注意的是:

size_t mbstowcs(wchar_t *wcstr,const char *mbstr,size_t count);

这个函数的第三个参数count，大小一定要是mbstr长度的2倍，否则出来的中文也会是乱码。

测试一下：

setlocale(LC_ALL,"zh_CN.GB18030");
wchar_t wcstr[20] = L"字符测试123abc";

int len = wcslen(wcstr)+1;
printf("len = %d \n",len);
for(int i = 0; i < len; i++)
printf("0x%08x ",wcstr[i]);
printf("\n");

char str[55] = {0};
int n = wcstombs(str,wcstr,55);
if(-1 == n)
{
perror("wcstombs ");
exit(-1);
}
printf("n = %d\n",n);
for(int i = 0; i < n+1; i++)
printf("0x%08x ",str[i]);
printf("\n");
wchar_t wch[50]={0};
int m = mbstowcs(wch,str,n);
if(m == -1)
{
perror("Converting");
exit(-1);
}
printf("m = %d\n",m);
for(int i =0; i printf("0x%08x ",wch[i]);
printf("\n");
return 0;
}

还有呢，转码还可以使iconv函数族，包含以下三个函数：
iconv_t iconv_open(const char *tocode, const char *fromcode);

size_t iconv(iconv_t cd,char **inbuf,size_t *inbytesleft,char **outbuf,size_t *outbytesleft);

int iconv_close(iconv_t cd);

测试一下：

#include
#include
#include

#define BUFLEN 256

char outbuf[BUFLEN];
char inbuf[BUFLEN] = "characters convertion";

int main()
{
char *pin = inbuf;
char *pout = outbuf;

int inlen = strlen(pin);
int outlen = BUFLEN;

int retsize;

iconv_t cd;

cd = iconv_open("UTF-8", "GBK");

if((iconv_t)-1 == cd) {
perror("iconv_open error");
return -1;
}

retsize = iconv(cd, &pin, (size_t *)&inlen, &pout, (size_t *)&outlen);

if((size_t)-1 == retsize) {
perror("iconv error");
return -2;
}

if(outlen > 0) {
printf("%s\n", outbuf);
}

iconv_close(cd);

return 0;
}