#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iconv.h>
#define OUTLEN 255
/* 用 file a.out 来看输出文件的编码*/
int main()
{
  char  buf[255];
  char out[OUTLEN];
  int rec;

  FILE *fin = fopen("/tmp/a.in", "r");
  FILE *fout = fopen("a.out", "w");
  fscanf(fin,"%s\n",buf);
  rec = g2u(buf,strlen(buf),out,OUTLEN);
  fprintf (fout,"%s\n",out);
  /* fprintf (fout,"%s\n",buf); */

  fclose(fout);
  fclose(fin);
  return 0;
}
//代码转换:从一种编码转为另一种编码
int code_convert(char *from_charset, char *to_charset, char *inbuf, int inlen,
                 char *outbuf, int outlen) {
  iconv_t cd;
  int rc;
  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;
}
//UNICODE码转为GB2312码
int u2g(char *inbuf, int inlen, char *outbuf, int outlen) {
  return code_convert("utf-8", "gb2312", inbuf, inlen, outbuf, outlen);
}
//GB2312码转为UNICODE码
int g2u(char *inbuf, size_t inlen, char *outbuf, size_t outlen) {
  return code_convert("gb2312", "utf-8", inbuf, inlen, outbuf, outlen);
}