di is a disk information utility, displaying everything (and more) that your 'df' command does. It features the ability to display your disk usage in whatever format you desire/prefer/are used to. It is designed to be portable across many platforms.
Dialog is a utility to create nice user interfaces to shell scripts, or other scripting languages, such as perl. It is non-graphical (it uses curses) so it can be run in the console or an xterm.
Directory Manager (dm) is a small tool for managing often-visited directories using a shell like bash.
dirtree is a tool for displaying directories. It supports an easier interface than du for combining directory trees and shell scripts.
dl is a perl script which provides a quick solution to the difficulty of recovering deleted files on most UNIX filesystems. Files given to dl are compressed, moved to a private backup directory, and deleted only when they haven't been recovered after a configurable amount of time.
dnotify is a simple program that makes it possible to execute a command every time the contents of a specific directory change in linux. It is run from the command line and takes two arguments: one or more directories to monitor and a command to execute whenever a directory has changed. Options control what events to trigger on: when a file was read in the directory, when one was created, deleted and so on.
a collection of all the free software tools you need to work on and format DocBook documents. RPMs are provided for those using RedHat Linux; the sourceware are all conveniently available from a single place if you're using some other OS
dog is a replacement for cat.
provides a selection of features allowing manipulation of text files in a mixed DOS/Windows and Unix environment
drm_tools contains several small utilities: accudate, execinput, extract, mdump, and msgqueue. accudate is a date replacement with subsecond accuracy. execinput executes commands one at a time from stdin. extract extracts and then emits column/token fields. mdump formats binary data files. msgqueue provides command line control of message queues.
DRS Looper is a program for running a list of commands, a certain number of commands at a time. It facilitates a variety of forms of parameterization, including hostnames for ssh or rsync.
The DSI utilities are a mixed collection of classes accumulated during the last ten years in projects developed at the DSI (Dipartimento di Scienze dell'Informazione, i.e., Information Sciences Department) of the UniversitÓ degli Studi di Milano.
DTPSTree shows the running processes as a tree. It is a reimplementation of pstree from PSmisc for FreeBSD.
du (abbreviated from disk usage) is a standard utility used to estimate the file space usage; space being used under a particular directory or files on a file system. Read more
scans a UNIX directory tree looking for pairs of distinct files with identical content. When it finds such files, it deletes one file to reclaim its disk space and then recreates its path name as a link to the other copy