For each file that is a directory, ls lists the contents of the directory. For each file that is an ordinary file, 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 for output directed to a terminal is multi-column with entries sorted down the columns. The -1 option allows single column output and -m 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 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.

D

The entry is a door.

l

The entry is a symbolic link.

b

The entry is a block special file.

c

The entry is a character special file.

p

The entry is a FIFO (or "named pipe") special file.

s

The entry is an AF_UNIX address family socket.

-

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 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. The character after permissions is ACL indication. A plus sign is displayed if there is an ACL associated with the file. Nothing is displayed if there are just permissions.

ls -l (the long list) prints its output as follows for the POSIX locale:

-rwxrwxrwx+ 1 smith dev 10876 May 16 9:42 part2

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 contains 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 (see cp(1)). The plus sign indicates that there is an ACL associated with the file. Note: If the -@ option has been specified, the presence of extended attributes will supersede the presence of an ACL and the plus sign will be replaced with an 'at' sign (@). Finally, the dash and letters tell you that user, group, and others have permissions to read, write, and 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.

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 chmod(1)), and execution is on.

T

The 1000 bit is turned on, and execution is off (undefined bit-state).

/usr/bin/ls

/usr/xpg4/bin/ls

The following options are supported:

-a

Lists all entries, including those that begin with a dot (.), which are normally not listed.

-A

Lists all entries, including those that begin with a dot (.), with the exception of the working directory (.) and the parent directory (..).

-b

Forces printing of non-printable characters to be in the octal \ddd notation.

-c

Uses time of last modification of the i-node (file created, mode changed, and so forth) for sorting (-t) or printing (-l or -n).

-C

Multi-column output with entries sorted down the columns. This is the default output format.

-d

If an argument is a directory, lists only its name (not its contents). Often used with -l to get the status of a directory.

-f

Forces 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.

-F

Marks directories with a trailing slash (/), doors with a trailing greater-than sign (>), executable files with a trailing asterisk (*), FIFOs with a trailing vertical bar (|), symbolic links with a trailing 'at' sign (@), and AF_UNIX address family sockets with a trailing equals sign (=).

-g

The same as -l, except that the owner is not printed.

-h

All sizes are scaled to a human readable format, for example, 14K, 234M, 2.7G, or 3.0T. Scaling is done by repetitively dividing by 1024.

-i

For each file, prints the i-node number in the first column of the report.

-l

Lists in long format, giving mode, ACL indication, number of links, owner, group, size in bytes, and time of last modification for each file (see above). If the file is a special file, the size field instead contains the major and minor device numbers. If the time of last modification is greater than six months ago, it is shown in the format `month date year' for the POSIX locale. When the LC_TIME locale category is not set to the POSIX locale, a different format of the time field may be used. Files modified within six months show `month date time'. If the file is a symbolic link, the filename is printed followed by "->" and the path name of the referenced file.

-L

If an argument is a symbolic link, lists the file or directory the link references rather than the link itself.

-m

Streams output format. Files are listed across the page, separated by commas.

-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.

-p

Puts a slash (/) after each filename if the file is a directory.

-q

Forces printing of non-printable characters in file names as the character question mark (?).

-r

Reverses the order of sort to get reverse alphabetic or oldest first as appropriate.

-R

Recursively lists subdirectories encountered.

-s

Gives size in blocks, including indirect blocks, for each entry.

-t

Sorts by time stamp (latest first) instead of by name. The default is the last modification time. (See -u and -c.)

-u

Uses time of last access instead of last modification for sorting (with the -t option) or printing (with the -l option).

-@

The same as -l, except that extended attribute information will supersede ACL information. An @ is displayed after the file permission bits for files that have extended attributes.

-x

Multi-column output with entries sorted across rather than down the page.

-1

Prints one entry per line of output.

/usr/bin/ls

/usr/xpg4/bin/ls

The following operand is supported:

file

A path name of a file to be written. If the file specified is not found, a diagnostic message will be output on standard error.

See largefile(5) for the description of the behavior of ls when encountering files greater than or equal to 2 Gbyte ( 2³¹ bytes).

See environ(5) for descriptions of the following environment variables that affect the execution of ls: LC_COLLATE, LC_CTYPE, LC_TIME, LC_MESSAGES, NLSPATH, and TZ.

COLUMNS

Determines the user's preferred column position width for writing multiple text-column output. If this variable contains a string representing a decimal integer, the ls utility calculates how many path name text columns to write (see -C) based on the width provided. If COLUMNS is not set or is invalid, 80 is used. The column width chosen to write the names of files in any given directory will be constant. File names will not be truncated to fit into the multiple text-column output.

0

All information was written successfully.

>0

An error occurred.

/etc/group

group IDs for ls -l and ls -g

/etc/passwd

user IDs for ls -l and ls -o

/usr/share/lib/terminfo/?/*

terminal information database

See attributes(5) for descriptions of the following attributes:

/usr/bin/ls

/usr/xpg4/bin/ls

chmod(1), cp(1), setfacl(1), terminfo(4), attributes(5), environ(5), fsattr(5), largefile(5), XPG4(5)

Unprintable characters in file names may confuse the columnar output options.

The total block count will be incorrect if there are hard links among the files.

The sort order of ls output is affected by the locale and can be overridden by the LC_COLLATE environment variable. For example, if LC_COLLATE equals C, dot files appear first, followed by names beginning with upper-case letters, then followed by names beginning with lower-case letters. But if LC_COLLATE equals en_US.ISO8859-1, then leading dots as well as case are ignored in determining the sort order.