network

netcat : NC(1) BSD General Commands Manual NC(1) nc — arbitrary TCP and UDP connections and listens
ping : 6 send ICMP ECHO_REQUEST to network hosts
nmcli : – commandline tool for controlling NetworkManager
telnet : user interface to the TELNET protocol
openssl : OpenSSL command line tool
sftp : secure file transfer program
...

shell

busybox : The Swiss Army Knife of Embedded Linux
gnome-terminal : is a terminal emulation application.
which : locate a command
fusermount : mount and unmount FUSE filesystems
watch : execute a program periodically, showing output fullscreen
locale : specific information.
...

filesystem

resize2fs : ext2/ext3/ext4 file system resizer
fsck : check and repair a Linux filesystem
chown : change file owner and group
passwd : change user password
mkfs : build a Linux filesystem
rename : renames multiple files
...

programming

strace : trace system calls and signals
startpar : start runlevel scripts in parallel
MAKEDEV : create devices
busybox : The Swiss Army Knife of Embedded Linux
kmk_sed : framework for writing simple makefiles for complex tasks
setkeycodes : load kernel scancode-to-keycode mapping table entries
...

file

mkfs.ext2 : create an ext2/ext3/ext4 filesystem
egrep : , fgrep, rgrep print lines matching a pattern
hexdump : , hd ASCII, decimal, hexadecimal, octal dump
passwd : change user password
su : change user ID or become superuser
fsck.ext3 : check a Linux ext2/ext3/ext4 file system
...

graphic manipulation

gimp : an image manipulation and paint program.
start-stop-daemon : start and stop system daemon programs
animate : animates an image or image sequence on any X server.
pamstretch-gen : use pamstretch and pnmscale to scale by non-integer values
tiff2rgba : convert a TIFF image to RGBA color space
sha1sum : compute and check SHA1 message digest
...

database

mysqlimport : a data import program
mysqld_safe : MySQL server startup script
nm-tool : utility to report NetworkManager state and devices
telnet : user interface to the TELNET protocol
arch : print machine hardware name (same as uname -m)
rmsgmerge : Extract translatable string from given input ruby script files.
...

X

gnome-terminal : is a terminal emulation application.
xfreerdp : FreeRDP X11 client
nohup : run a command immune to hangups, with output to a non-tty
svlc : , nvlc, rvlc, cvlc the VLC media player
xsetpointer : set an X Input device as the main pointer
pdb3.3 : the Python debugger
...

package management

update-grub : stub for grub-mkconfig
pk2bm : create a bitmap from a TeX pkfont
dvdrip : GUI for copying DVDs
pdb3.3 : the Python debugger
bzip2 : recover recovers data from damaged bzip2 files
nohup : run a command immune to hangups, with output to a non-tty
...

printer

ppdc : cups ppd compiler
ghostscript : Ghostscript (PostScript and PDF language interpreter and previewer)
sldtoppm : convert an AutoCAD slide file into a portable pixmap
lprm : cancel print jobs
sensible-pager : pager, sensible-browser - sensible editing, paging, and web browsing
cweave : translate CWEB to C and/or TeX
...

text manipulation

loadunimap : load the kernel unicode-to-font mapping table
awk : pattern scanning and processing language
dvdrip : GUI for copying DVDs
sha1sum : compute and check SHA1 message digest
nohup : run a command immune to hangups, with output to a non-tty
nl : number lines of files
...

privacy

passwd : change user password
tor-gencert : Generate certs and keys for Tor directory authorities
lame : create mp3 audio files
start-stop-daemon : start and stop system daemon programs
wpa_passphrase : Generate a WPA PSK from an ASCII passphrase for a SSID
gpgsplit : Split an OpenPGP message into packets
...

sound manipulation

audacity : Graphical cross-platform audio editor
gst-launch-1.0 : build and run a GStreamer pipeline
ping : 6 send ICMP ECHO_REQUEST to network hosts
cweave : translate CWEB to C and/or TeX
jack_samplerate : JACK toolkit client to print current samplerate
airtun-ng : a virtual tunnel interface creator for aircrack-ng
...

Access Control List

su : change user ID or become superuser
MAKEDEV : create devices
update-grub : stub for grub-mkconfig
uic :
start-stop-daemon : start and stop system daemon programs
nohup : run a command immune to hangups, with output to a non-tty
...

file compression

pdb3.3 : the Python debugger
scp-dbus-service :
file-roller : archive manager for GNOME
lzcat : Compress or decompress .xz and .lzma files
airtun-ng : a virtual tunnel interface creator for aircrack-ng
nohup : run a command immune to hangups, with output to a non-tty
...

boot settings

update-grub : stub for grub-mkconfig
syslinux : install the SYSLINUX bootloader on a FAT filesystem
iconv : Convert encoding of given files from one encoding to another
nohup : run a command immune to hangups, with output to a non-tty
pdb3.3 : the Python debugger
airtun-ng : a virtual tunnel interface creator for aircrack-ng
...

text editor

start-stop-daemon : start and stop system daemon programs
parted : GNU Parted - a partition manipulation program
airtun-ng : a virtual tunnel interface creator for aircrack-ng
2to3-3.2 : Python2 to Python3 converter
fmtutil-sys : utility for maintaining TeX format files system-wide
pdb3.3 : the Python debugger
...

webserver

a2ensite : enable or disable an apache2 site / virtual host
ping : 6 send ICMP ECHO_REQUEST to network hosts
start-stop-daemon : start and stop system daemon programs
dh_installppp : install ppp ip-up and ip-down files
spd-conf : A simple tool for basic configuration of Speech Dispatcher and problem diagnostics
gst-launch-1.0 : build and run a GStreamer pipeline
...

font

spd-conf : A simple tool for basic configuration of Speech Dispatcher and problem diagnostics
debugfs : ext2/ext3/ext4 file system debugger
ofm2opl : convert Omega and TeX font-metric files to property-list files
passwd : change user password
cweave : translate CWEB to C and/or TeX
mft : translate Metafont or MetaPost code to TeX code for prettyprinting
...

mail

lame : create mp3 audio files
loadunimap : load the kernel unicode-to-font mapping table
mimeopen : Open files by mimetype
lockfile-remove : command-line programs to safely lock and unlock files and mailboxes (via liblockfile).
spd-conf : A simple tool for basic configuration of Speech Dispatcher and problem diagnostics
nohup : run a command immune to hangups, with output to a non-tty
...

Media Player

spd-conf : A simple tool for basic configuration of Speech Dispatcher and problem diagnostics
update-grub : stub for grub-mkconfig
passwd : change user password
cweave : translate CWEB to C and/or TeX
avifix : fix header of AVI-file
airtun-ng : a virtual tunnel interface creator for aircrack-ng
...

virtualization

ping : 6 send ICMP ECHO_REQUEST to network hosts
start-stop-daemon : start and stop system daemon programs
VBoxControl : x86 virtualization solution
spd-conf : A simple tool for basic configuration of Speech Dispatcher and problem diagnostics
nohup : run a command immune to hangups, with output to a non-tty
passwd : change user password
...

help us categorise commands