c语言的字符集转换，出错了，求解！

sdpwlf1982

各位：我是个新手，从网上学习一个字符集转换的代码，
___________________
#include <iconv.h>
#define OUTLEN 255
main()
{
char *in_utf8 = "姝ｅ?ㄥ??瑁?";
char *in_gb2312 = "正在安装";
char out[OUTLEN];
int rc;

//unicode码转为gb2312码
rc = u2g(in_utf8,strlen(in_utf,out,OUTLEN);
printf("unicode-->gb2312 out=%sn",out);
//gb2312码转为unicode码
rc = g2u(in_gb2312,strlen(in_gb2312),out,OUTLEN);
printf("gb2312-->unicode out=%sn",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;
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);
}
_____________________________________________________
在编译的时候，报这样的错误

cc:  487: warning : Possibly incorrect message catalog.
cc: "sdp.c",  26:  604: , line : warning : Pointers are not assignment-compatib.
cc: "sdp.c",  26:  563: , line : warning #3: Argument  is not the correct type.
cc: "sdp.c",  26:  604: , line : warning : Pointers are not assignment-compatib.
cc: "sdp.c",  26:  563: , line : warning #5: Argument  is not the correct type.


请各位不吝指教一下！多谢！