LS(1) (Essential Utilities) LS(1)
NAME
ls - list contents of directory
SYNOPSIS
ls [-RadLCxmlnogrtucpFbqisf] [names]
DESCRIPTION
For each directory argument, ls lists the contents of the
directory; for each file argument, ls repeats its name and
any other information requested. The output is sorted
alphabetically by default. When no argument is given, the
current directory is listed. When several arguments are
given, the arguments are first sorted appropriately, but
file arguments appear before directories and their contents.
There are three major listing formats. The default format
is to list one entry per line, the -C and -x options enable
multi-column formats, and the -m option enables stream
output format. In order to determine output formats for the
-C, -x, and -m options, ls uses an environment variable,
COLUMNS, to determine the number of character positions
available on one output line. If this variable is not set,
the terminfo(4) database is used to determine the number of
columns, based on the environment variable TERM. If this
information cannot be obtained, 80 columns are assumed.
The ls command has the following options:
-R Recursively list subdirectories encountered.
-a List all entries, including those that begin with a dot
(.), which are normally not listed.
-d If an argument is a directory, list only its name (not
its contents); often used with -l to get the status of
a directory.
-L If an argument is a symbolic link, list the file or
directory the link references rather than the link
itself.
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-C Multi-column output with entries sorted down the
columns.
-x Multi-column output with entries sorted across rather
than down the page.
-m Stream output format; files are listed across the page,
separated by commas.
-l List in long format, giving mode, number of links,
owner, group, size in bytes, and time of last
modification for each file (see below). If the file is
a special file, the size field will instead contain the
major and minor device numbers rather than a size.
-n The same as -l, except that the owner's UID and group's
GID numbers are printed, rather than the associated
character strings.
-o The same as -l, except that the group is not printed.
-g The same as -l, except that the owner is not printed.
-r Reverse the order of sort to get reverse alphabetic or
oldest first as appropriate.
-t Sort by time stamp (latest first) instead of by name.
The default is the last modification time. (See -n and
-c.)
-u Use time of last access instead of last modification
for sorting (with the -t option) or printing (with the
-l option).
-c Use time of last modification of the i-node (file
created, mode changed, etc.) for sorting (-t) or
printing (-l).
-p Put a slash (/) after each filename if that file is a
directory.
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-F Put a slash (/) after each filename if that file is a
directory, an asterisk (*) after each filename if that
file is executable, and an at-sign (@) after each
filename if that file is a symbolic link.
-b Force printing of non-printable characters to be in the
octal \ddd notation.
-q Force printing of non-printable characters in file
names as the character question mark (?).
-i For each file, print the i-number in the first column
of the report.
-s Give size in blocks, including indirect blocks, for
each entry.
-f Force each argument to be interpreted as a directory
and list the name found in each slot. This option
turns off -l, -t, -s, and -r, and turns on -a; the
order is the order in which entries appear in the
directory.
The mode printed under the -l option consists of ten
characters. The first character may be one of the
following:
d the entry is a directory;
b the entry is a block special file;
c the entry is a character special file;
l the entry is a symbolic link;
p the entry is a fifo (a.k.a. "named pipe") special
file;
- the entry is an ordinary file.
The next 9 characters are interpreted as three sets of three
bits each. The first set refers to the owner's permissions;
the next to permissions of others in the user-group of the
file; and the last to all others. Within each set, the
three characters indicate permission to read, to write, and
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to execute the file as a program, respectively. For a
directory, "execute" permission is interpreted to mean
permission to search the directory for a specified file.
ls -l (the long list) prints its output as follows:
-rwxrwxrwx 1 smith dev 10876 May 16 9:42 part2
This horizontal configuration provides a good deal of
information. Reading from right to left, you see that the
current directory holds one file, named "part2." Next, the
last time that file's contents were modified was 9:42 A.M.
on May 16. The file is moderately sized, containing 10,876
characters, or bytes. The owner of the file, or the user,
belongs to the group "dev" (perhaps indicating
"development"), and his or her login name is "smith." The
number, in this case "1," indicates the number of links to
file "part2." Finally, the row of dash and letters tell you
that user, group, and others have permissions to read,
write, execute "part2."
The execute (x) symbol here occupies the third position of
the three-character sequence. A - in the third position
would have indicated a denial of execution permissions.
The permissions are indicated as follows:
r the file is readable
w the file is writable
x the file is executable
- the indicated permission is not granted
l mandatory locking will occur during access (the
set-group-ID bit is on and the group execution bit
is off)
s the set-user-ID or set-group-ID bit is on, and the
corresponding user or group execution bit is also
on
S undefined bit-state (the set-user-ID bit is on and
the user execution bit is off)
t the 1000 (octal) bit, or sticky bit, is on (see
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chmod(1)), and execution is on
T the 1000 bit is turned on, and execution is off
(undefined bit-state)
For user and group permissions, the third position is
sometimes occupied by a character other than x or -. s also
may occupy this position, referring to the state of the
set-ID bit, whether it be the user's or the group's. The
ability to assume the same ID as the user during execution
is, for example, used during login when you begin as root
but need to assume the identity of the user stated at
"login."
In the case of the sequence of group permissions, l may
occupy the third position. l refers to mandatory file and
record locking. This permission describes a file's ability
to allow other files to lock its reading or writing
permissions during access.
For others permissions, the third position may be occupied
by t or T. These refer to the state of the sticky bit and
execution permissions.
EXAMPLES
An example of a file's permissions is:
-rwxr--r--
This describes a file that is readable, writable, and
executable by the user and readable by the group and others.
Another example of a file's permissions is:
-rwsr-xr-x
This describes a file that is readable, writable, and
executable by the user, readable and executable by the group
and others, and allows its user-ID to be assumed, during
execution, by the user presently executing it.
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Another example of a file's permissions is:
-rw-rwl---
This describes a file that is readable and writable only by
the user and the group and can be locked during access.
An example of a command line:
ls -a
This command will print the names of all files in the
current directory, including those that begin with a dot
(.), which normally do not print.
Another example of a command line:
ls -aisn
This command will provide you with quite a bit of
information including all files, including non-printing ones
(a), the i-number-the memory address of the i-node
associated with the file-printed in the left-hand column
(i); the size (in blocks) of the files, printed in the
column to the right of the i-numbers (s); finally, the
report is displayed in the numeric version of the long list,
printing the UID (instead of user name) and GID (instead of
group name) numbers associated with the files.
When the sizes of the files in a directory are listed, a
total count of blocks, including indirect blocks, is
printed.
FILES
/etc/passwd user IDs for ls -l and ls -o
/etc/group group IDs for ls -l and ls -g
/usr/lib/terminfo/?/* terminal information database
SEE ALSO
chmod(1), find(1).
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NOTES
In a Remote File Sharing environment, you may not have the
permissions that the output of the ls -l command leads you
to believe. For more information, see the "Mapping Remote
Users" section of Chapter 10 of the System Administrator's
Guide.
BUGS
Unprintable characters in file names may confuse the
columnar output options.
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