Tree (command)

In computing, codice_1 is a recursive directory listing command or program that produces a depth-indented listing of files. Originating in PC- and MS-DOS, it is found in Digital Research FlexOS, IBM/Toshiba 4690 OS, PTS-DOS, FreeDOS, IBM OS/2, Microsoft Windows, and ReactOS. A version for Unix and Unix-like systems is also available. 
The codice_1 command is frequently used as part of a technical support scam, where the command is used to occupy the command prompt screen, while the scammer, pretending to be technical support, types additional text that is supposed to look like output of the command.
Overview.
With no arguments, codice_1 lists the files in the current directory. When directory arguments are given, codice_1 lists all the files or directories found in the given directories each in turn. Upon completion of listing all files and directories found, codice_1 returns the total number of files and directories listed. There are options to change the characters used in the output, and to use color output.
The command is available in MS-DOS versions 3.2 and later and IBM PC DOS releases 2 and later. Digital Research DR DOS 6.0, Itautec SISNE plus, and Datalight ROM-DOS include an implementation of the command.
The "Tree" Unix utility was developed by Steve Baker. The FreeDOS version was developed by Dave Dunfield and the ReactOS version was developed by Asif Bahrainwala. All three implementations are licensed under the GNU General Public License.
Example.
$ tree path/to/folder/
path/to/folder/
├── a-first.html
├── b-second.html
├── subfolder
│ ├── readme.html
│ ├── code.cpp
│ └── code.h
└── z-last-file.html
1 directories, 6 files