The system handles files and directories in the same way; directories are
just specialized files, containing other files and directories rather
than program code or text. Files and directories both have a name, a
path, and a set of attributes. Internally, the system keeps track of
files and directories using inodes, or index nodes. See
``How the system manages files and directories''.
A simple way of checking some of the attributes of a file or
directory is the long listing, obtained using the
-l option to the
ls(C)
command (or just l):
What you see in a long listing
The first field (file type) indicates the sort of file that is
present in the listing. The following codes are some of those used
(for a full list, see
ls(C)):
-
ordinary file
b
block special file
c
character special file
d
directory
l
symbolic link
p
named pipe
The second field (permissions) shows who is permitted to read,
write, or execute a file, or change to a directory. Users are
split into the file's owner, people in the same work group as the
owner, and other people. A separate set of permissions is
maintained for each category. The notation used here is
explained in detail in
``Access control for files and directories''.
The fourth field (owner) shows the login name of the owner of the
file.
The fifth field (group) shows the group to which the file belongs;
that is, the group of users who have ``group'' access permission to
the file. See
``Finding out your group''
for an explanation of groups.
The sixth field (size) shows the number of bytes in the file.
The seventh and eighth fields (date and time of last modification)
show the date and time when the file was last modified.
The final field (filename) shows the name of the file. See
``Filenaming conventions''
for more on filenames.
