求解：如何用C把文件从后往前读取

求解：怎么用C把文件从后往前读取
要求：
          打印出文件最后一行，然后倒数第二行，第三行，一次类推




[解决办法]
fseek到末尾，然后向移动到到上一个结束符，然后去后面字符
[解决办法]
将文件按行读出，存入一个字符指针数组，逆序输出，如果文件大，分块
[解决办法]

C/C++ code

#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>void tail(int fd, int nline);int main(int argc, char *argv[]){    int line;    char *fname;    int fd;    if (argc != 3) {        fprintf(stderr, "Usage: a.out line file\n");        exit(1);    }    line = atoi(argv[1]);    fname = argv[2];    if ((fd = open(fname, O_RDONLY)) == 0) {        perror(NULL);        exit(1);    }    tail(fd, line);    close(fd);    return 0;}void tail(int fd, int nline){    char buf[100] = { 0 };    long n = 0;    nline++;    while (lseek(fd, n, SEEK_END) && nline) {        read(fd, buf, 1);        if (!strcmp(buf, "\n"))            nline--;        n--;    }        n += 2;            /*read postion is before "\n", add 2 to skip to the next line's start */    lseek(fd, n, SEEK_END);        while (read(fd, buf, 1))        write(1, buf, 1);}