p3-2.c

来自「UNIX程序设计教程」· C语言 代码 · 共 24 行

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include "err_exit.h"
char bufl[] = "abcdefghij";
char buf2[] = "ABCDEFGHIJ";
int main (void)
{
    int fd;
    if ((fd = open("file.hole",O_WRONLY|O_CREAT/*|O_APPEND*/, 0644)) < 0)
        err_exit("creat error" );
    if (write (fd, bufl, 10) != 10)
        err_exit("buf1 write error");
    /* 文件位置现在为10 */
    if (lseek(fd, 40, SEEK_SET) == -1)
        err_exit("lseek error");
    /* 文件位置现在为40 */
    if (write (fd, buf2, 10) != 10)
       err_exit("buf2 write error");
    /* 文件位置现在为50 */
    exit(0);
}