Display information about one or more files.
ls [options] file-list
The ls utility displays information about one or more files. It lists the information alphabetically by filename unless you use an option to change the order.
When you do not use an argument, ls displays the names of the files in the working directory. If you do not use the -a option, ls does not list files whose filenames begin with ..
The file-list contains one or more pathnames of files. You can use the pathname of any ordinary, directory, or device file. These pathnames can include ambiguous file references.
When you specify a directory, ls displays the contents of the directory. The ls utility displays the name of the directory only when it is needed to avoid ambiguity (that is, when ls is displaying the contents of more than one directory, it displays the names of the directories to indicate which files you can find in which directory). If you specify an ordinary file, ls displays information about just that file.
The options determine the type of information ls displays, how it displays it, and the order in which it is displayed.
When you do not use an option, ls displays a short listing, containing only the names of files.
||all entries Without a file-list (no arguments on the command line), this option displays information about all the files in the working directory, including invisible files (those with filenames that begin with a period). When you do not use this option, ls does not list information about invisible files, unless you list the name of an invisible file in file-list.
In a similar manner, when you use this option with a file-list that includes an appropriate ambiguous file reference, ls displays information about invisible files. (The
||directory This option displays the names of directories without displaying their contents. When you give this option without an argument, ls displays information about the working directory. This option displays ordinary files normally.|
||long This option displays several columns of information about each file.|
||symbolic link When you use this option, ls lists information about the file referenced by each symbolic link rather than information about the link itself.|
The -l option displays the seven columns shown in the figure to the right. The first column, which contains 10 characters, is divided as follows. The first character describes the type of file:
|First Character||Type of File|
The next nine characters represent all the access permissions associated with the file. These nine characters are divided into three sets of three characters each.
The first three character's represent the owner's access permissions. If the owner has read access permission, an r appears in the first character position. If the owner is not permitted to read the file, a hyphen appears in this position. The next two positions represent the owner's write and execute access permissions. A w appears in the second position if the owner is permitted to write to the file, and an x appears in the third position if the owner is permitted to execute the file.
In a similar manner, the second and third sets of three characters represent the access permissions of the owner's group and other users.
The second column indicates the number of hard links to the file.
The third and fourth columns display the name of the owner of the file and the name of the group the file belongs to.
The fifth column indicates the size of the file in bytes. In the case of a directory, this number is the size of the actual directory file, not the size of the files that are entries within the directory.
The last two columns display the date and time the file was last modified, and the filename.
The departmental Unix servers,
hopper, display certain types of filenames in colors other than the default white:
All of the following examples assume that the user does not change to another working directory.
The first command line shows the default behavior of the ls utility. You see an alphabetical list of the names of the files in the working directory.
z123456@turing:~$ ls bin csci241 prog1.cpp public_html text
Next, the -l (long) option displays a long list. The files are still in alphabetical order.
z123456@turing:~$ ls -l total 20 drwxr-xr-x 2 z123456 csci 4096 2010-08-21 10:58 bin drwxr-xr-x 9 z123456 csci 4096 2010-07-01 12:19 csci241 -rw-r--r-- 1 z123456 csci 111 2010-12-20 20:59 prog1.cpp lrwxrwxrwx 1 root root 29 2008-10-23 16:04 public_html -> /home/www/z123456/public_html -rw-r--r-- 1 z123456 csci 11 2010-12-27 11:18 text
The -a (all) option lists all files, including invisible ones.
z123456@turing:~$ ls -a . .bash_history bin prog1.cpp text .. .bashrc csci241 public_html
Combining the -a and -l options displays a long listing of all the files, including invisible files, in the working directory. This list is still in alphabetical order.
z123456@turing:~$ ls -al total 68 drwxr-xr-x 12 z123456 csci 4096 2010-12-27 11:18 . drwxr-xr-x 891 root root 20480 2010-10-06 13:24 .. -rw------- 1 z123456 csci 7842 2010-12-27 10:52 .bash_history -rw-r--r-- 1 z123456 csci 37 2010-07-27 10:54 .bashrc drwxr-xr-x 2 z123456 csci 4096 2010-08-21 10:58 bin drwxr-xr-x 9 z123456 csci 4096 2010-07-01 12:19 csci241 -rw-r--r-- 1 z123456 csci 111 2010-12-20 20:59 prog1.cpp lrwxrwxrwx 1 root root 29 2008-10-23 16:04 public_html -> /home/www/z123456/public_html -rw-r--r-- 1 z123456 csci 11 2010-12-27 11:18 text
The next example shows ls with a directory filename as an argument. The ls utility lists the contents of the directory in alphabetical order.
z123456@turing:~$ ls bin mailprog.241
To display information about the directory itself, use the -d (directory) option. This option causes ls to list information only about the directory.
z123456@turing:~$ ls -dl bin drwxr-xr-x 2 z123456 csci 4096 2010-08-21 10:58 bin