c/c++文件相关

取的文件大小

1. int fd = open("data.txt",O_RDONLY);

int len = lseek(fd,0,SEEK_END);

2. struct stat sb;

if ((fstat(fd, &sb)) == -1) {

perror("fstat");
}

sb.st_size

3.

if ((mapped = (char *)mmap(NULL, sb.st_size, PROT_READ |

PROT_WRITE, MAP_PRIVATE, fd, 0)) == (void *)-1) {

perror("mmap");

}

1. if ((mapped = (char *)mmap(NULL, sb.st_size, PROT_READ |


2. PROT_WRITE, MAP_PRIVATE, fd, 0)) == (void *)-1) {


3. perror("mmap");


4. }