我用C编写dll截取文本文件内容并返还回但是无法获得文件内容

#include
#define MAXLEN 16384
FILE *f;
long offset=12345;
long len=678;
char str[MAXLEN];
void main(int *p1,int *p2,char *msg,char *str1[MAXLEN]) {
//char *msg="D:\WisePOM_base\rawsitedata\20150211\001@20150211165316.txt";
//char *str1[MAXLEN];
char str2[MAXLEN];
//int *p1 = 0;
//int *p2 = 888;
int n = (int)p1;
int m = (int)p2;
strncpy(str2,msg,sizeof(str2));
f=fopen(str2,"rb");
fseek(f,n,SEEK_SET);
fread(str,1,m,f);
fclose(f);
str[len]=0;
*str1=str;
printf("%s",*str1);
system("pause");
return *str1;
}

没看懂，你要问问题。