dir (directory) is a command used for file and directory listing, specifically in the command line interface (CLI) of the operating systems RT-11, CP/M, VMS, DOS, OS/2, Singularity, and Microsoft Windows.
Because it is the primary means of displaying the files and directories on disk or other storage medium within a command window, the dir command is one of the most basic commands employed by users of the command line interface to MS-DOS and subsequent versions of Microsoft Windows.
dir command has existed as a DOS command since the initial release of MS-DOS. It is built into the DOS command shell, and is not provided as a separate standalone program.
In DOS and Microsoft Windows, dir checks for switches in the %dircmd% environment variable.
The following example demonstrates the output of the dir command on Windows 7, without arguments:
C:\Users\Public\Pictures\Sample Pictures>dir Volume in drive C is System Volume Serial Number is C8D0-76E2 Directory of C:\Users\Public\Pictures\Sample Pictures 14-07-2009 06:41 <DIR> . 14-07-2009 06:41 <DIR> .. 14-07-2009 06:52 879,394 Chrysanthemum.jpg 14-07-2009 06:52 845,941 Desert.jpg 14-07-2009 06:52 595,284 Hydrangeas.jpg 14-07-2009 06:52 775,702 Jellyfish.jpg 14-07-2009 06:52 780,831 Koala.jpg 14-07-2009 06:52 561,276 Lighthouse.jpg 14-07-2009 06:52 777,835 Penguins.jpg 14-07-2009 06:52 620,888 Tulips.jpg 8 File(s) 5,837,151 bytes 2 Dir(s) 57,925,980,160 bytes free C:\Users\Public\Pictures\Sample Pictures>dir /w Volume in drive C is System Volume Serial Number is C8D0-76E2 Directory of C:\Users\Public\Pictures\Sample Pictures [.] [..] Chrysanthemum.jpg Desert.jpg Hydrangeas.jpg Jellyfish.jpg Koala.jpg Lighthouse.jpg Penguins.jpg Tulips.jpg 8 File(s) 5,837,151 bytes 2 Dir(s) 57,925,992,448 bytes free C:\Users\Public\Pictures\Sample Pictures>
dir is not a Unix command, Unix has the analogous
ls command instead. The GNU/Linux operating system, however, has a
dir command that is equivalent to
ls -C -b; that is, by default files are listed in columns, sorted vertically, and special characters are represented by backslash escape sequences, as the documentation says.