Linux C 字符集转换,UTF-8,GB2312 
最近帮朋友写个系统接口的小东东，2个系统字符集不同，一个采用UTF-8,一个采用GB2312，不得已需要转换字符集。转换函数记录如下：

#include <iconv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define OUTLEN 255
main()
{
char *in_utf8 = "utf8字符串";
char *in_gb2312 = "\xbe\xb2\xcc\xac\xc4\xa3\xca\xbd";

char out[OUTLEN];
int rec ;

//unicode码转为gb2312码
rec = u2g(in_utf8,strlen(in_utf8),out,OUTLEN);
printf("unicode-->gb2312 out=%s\n",out);
  
//gb2312码转为unicode码
rec = g2u(in_gb2312,strlen(in_gb2312),out,OUTLEN);
printf("gb2312-->unicode out=%s \n",out);
}
//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);
}