Stat

• Needs sys/types.h
• Needs sys/stat.h
• Needs unistd.h
• int stat(const char *pathname, struct stat *buf);
• int fstat(int fd, struct stat *buf);
• int lstat(const char *pathname, struct stat *buf);
• Note that stat follows symbolic links, lstat does not.
• fstat works on file descriptors

• struct stat {
        dev_t     st_dev;         /* ID of device containing file */
        ino_t     st_ino;         /* inode number */
        mode_t    st_mode;        /* file type and mode */
        nlink_t   st_nlink;       /* number of hard links */
        uid_t     st_uid;         /* user ID of owner */
        gid_t     st_gid;         /* group ID of owner */
        dev_t     st_rdev;        /* device ID (if special file) */
        off_t     st_size;        /* total size, in bytes */
        blksize_t st_blksize;     /* blocksize for filesystem I/O */
        blkcnt_t  st_blocks;      /* number of 512B blocks allocated */
  
        /* Since Linux 2.6, the kernel supports nanosecond
           precision for the following timestamp fields.
           For the details before Linux 2.6, see NOTES. */
  
        struct timespec st_atim;  /* time of last access */
        struct timespec st_mtim;  /* time of last modification */
        struct timespec st_ctim;  /* time of last status change */
  
    #define st_atime st_atim.tv_sec      /* Backward compatibility */
    #define st_mtime st_mtim.tv_sec
    #define st_ctime st_ctim.tv_sec
  };
  

• The macros major and minor can be used to decode the st_dev field.
• There are a series of macros S_ISXXX() to identify the mode field
• see myls.C
• I don't plan on handling time this semester, but ctim will print a time field in a reasonable format.