struct stat {
mode_t st_mode; /* file type & mode (permissions) */
ino_t st_ino; /* i-node number (serial number) */
dev_t st_dev; /* device number (file system) */
dev_t st_rdev; /* device number for special files */
nlink_t st_nlink; /* number of links */
uid_t st_uid; /* user ID of owner */
gid_t st_gid; /* group ID of owner */
off_t st_size; /* size in bytes, for regular files */
time_t st_atime; /* time of last access */
time_t st_mtime; /* time of last modification */
time_t st_ctime; /* time of last file status change */
blksize_t st_blksize; /* best I/O block size */
blkcnt_t st_blocks; /* number of disk blocks allocated */
};atime 文件最近被访问的时间
mtime 文件最近被修改的时间，指内容被修改
ctime 文件状态最近被改变的时间，指改变文件状态，permission等
ls -l 命令默认打印文件的mtime，按字典顺序排序，-t 为按mtime排序
原文：http://my.oschina.net/u/2313065/blog/474702