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
MAKEDEV : create devices
busybox : The Swiss Army Knife of Embedded Linux
startpar : start runlevel scripts in parallel
ncurses5-config : helper script for ncurses libraries
ppmtosixel : convert a portable pixmap into DEC sixel format
...

file

passwd : change user password
su : change user ID or become superuser
mkfs.ext2 : create an ext2/ext3/ext4 filesystem
egrep : , fgrep, rgrep print lines matching a pattern
hexdump : , hd ASCII, decimal, hexadecimal, octal dump
rm : remove files or directories
...

graphic manipulation

gimp : an image manipulation and paint program.
start-stop-daemon : start and stop system daemon programs
bmp2tiff : create a TIFF file from a Microsoft Windows Device Independent Bitmap image file
MAKEDEV : create devices
debugfs : ext2/ext3/ext4 file system debugger
djpeg : decompress a JPEG file to an image file
...

database

mysqlimport : a data import program
mysqld_safe : MySQL server startup script
update-grub : stub for grub-mkconfig
time : run programs and summarize system resource usage
avconv : avconv video converter
getconf : Query system configuration variables
...

X

gnome-terminal : is a terminal emulation application.
xfreerdp : FreeRDP X11 client
gksudo : GTK+ frontend for su and sudo
xload : system load average display for X
passwd : change user password
start-stop-daemon : start and stop system daemon programs
...

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
kerneloops : program to collect and submit kernel oopses to kerneloops.org
loadunimap : load the kernel unicode-to-font mapping table
chroot : run command or interactive shell with special root directory
tor : The second-generation onion router
iconv : Convert encoding of given files from one encoding to another
...

sound manipulation

audacity : Graphical cross-platform audio editor
gst-launch-1.0 : build and run a GStreamer pipeline
avconv : avconv video converter
pdb3.3 : the Python debugger
sha1sum : compute and check SHA1 message digest
jack_evmon :
...

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

tcmp3cut :
erb1.8 : an embedded Ruby language interpreter
start-stop-daemon : start and stop system daemon programs
ping : 6 send ICMP ECHO_REQUEST to network hosts
showkey : examine the codes sent by the keyboard
dbus-send : Send a message to a message bus
...

text editor

find : search for files in a directory hierarchy
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
pgrep : , pkill look up or signal processes based on name and other attributes
passwd : change user password
start-stop-daemon : start and stop system daemon programs
...

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

iconv : Convert encoding of given files from one encoding to another
python2.7 : an interpreted, interactive, object-oriented programming language
kerneloops : program to collect and submit kernel oopses to kerneloops.org
loadunimap : load the kernel unicode-to-font mapping table
afm2tfm : convert Adobe font metrics to TeX font metrics
sha1sum : compute and check SHA1 message digest
...

mail

airtun-ng : a virtual tunnel interface creator for aircrack-ng
gst-launch-1.0 : build and run a GStreamer pipeline
passwd : change user password
cweave : translate CWEB to C and/or TeX
find : search for files in a directory hierarchy
thunderbird : Mail User Agent (MUA) and newsgroup/RSS client for X11 derived from the Mozilla suite.
...

Media Player

lame : create mp3 audio files
start-stop-daemon : start and stop system daemon programs
amarok : The audio player for KDE
gst-xmllaunch-0.10 : build and run a GStreamer pipeline from an XML serialization
sha1sum : compute and check SHA1 message digest
nohup : run a command immune to hangups, with output to a non-tty
...

virtualization

nohup : run a command immune to hangups, with output to a non-tty
passwd : change user password
cweave : translate CWEB to C and/or TeX
avconv : avconv video converter
airtun-ng : a virtual tunnel interface creator for aircrack-ng
update-grub : stub for grub-mkconfig
...

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