Dir (command)

dir, short for directory, is a shell command for listing file system contents: files and directories. Arguably, the command provides the same essential functionality as the ls command, but typically the two commands are described as notably separate concepts, possibly since is implemented from a codebase that shares more history than many implementations.
The command is often implemented as internal in the operating system shell instead of as a separate application as many other commands are.

Variants

Although syntax, semantics and implementations vary, a command with essentially the same functionality is available in the operating systems:
CP/M,
MP/M,
ISIS-II, iRMX 86,
CDOS,
TRIPOS,
DOS,
4690 OS,
OS/2,
Windows,
Singularity,
ROM-DOS,
ReactOS,
GNU#GNU as an [operating system|GNU],
AROS,
VMS,
RT-11,
RSX-11,
OS/8,
86-DOS,
MS-DOS,
and DOSBox.
Some applications also provide a command with similar functionality. The typical File Transfer Protocol command-line client provides a dir command for listing a remote directory. The numerical computing environments MATLAB and GNU Octave include a dir
command.
Generally, Unix-like systems use the command for the needs that dir satisfies in other types of systems. Notably, the Unix-like GNU operating system, provides 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.

Examples

List all files and directories in the working directory.
List text and batch files of the working directory by specifying filename extensions ".txt" or ".bat" with the "*" wildcard character that matches any base file name.
List files and directories in the specified directory and any subdirectories, recursively, in wide format, pausing after each screen of output. The directory name is enclosed in double-quotes, to prevent it from being interpreted is as two separate command-line options because it contains a space.
List any NTFS [junction point]s: