尝试使用这些函数复制文件,一切顺利,直到程序到达memcpy函数,这会产生总线错误并终止进程.
void copy_mmap(char* in,char* out){
int input_fd,output_fd;
input_fd = open (in,O_RDONLY);
if (input_fd == -1) {
printf("Error opening input file.\n");
exit(2);
}
output_fd = open(out,O_RDWR | O_CREAT,S_IWUSR | S_IRUSR);
if(output_fd == -1){
printf("Error opening output file.\n");
exit(3);
}
struct stat st;
fstat(input_fd,&st);
char* target;
target=mmap(0,st.st_size+1,PROT_READ,MAP_SHARED,input_fd,0);
if (target==(void*) -1){
printf("Error mapping target with errno: %d.\n",errno);
exit(6);
}
char* destination;
destination=mmap(0,PROT_READ | PROT_WRITE,output_fd,0);
if (destination==(void*) -1){
printf("Error mapping destination with errno: %d.\n",errno);
exit(5);
}
memcpy(destination,target,st.st_size);
munmap(destination,st.st_size);
}
最佳答案