Linux
Some useful commands
Free memory (2.2G/7.6G)
free -h | awk '/^Mem:/ {print $3 "/" $2}'
Top 10 most memory intensive processes
ps axch -o cmd:15,%mem --sort=-%mem | head
Top 10 most CPU intensive processes
ps axch -o cmd:15,%cpu --sort=-%cpu | head
Does your Terminal Emulator support Italics?
echo -e "\e[3m foo \e[23m"
dd
command usage to burn an iso to a flash drive
dd if=Downloads/archlinux-x86_64.iso of=/dev/sdb status=progress
Display the SSID of connected network
nmcli -t -f active,ssid dev wifi | egrep '^yes' | cut -d\' -f2
Colormap in terminal
msgcat --color=test
Set a random wallpaper from r/earthporn
wget -O - -q reddit.com/r/earthporn.json | jq '.data.children[] |.data.url' | head -1 | xargs feh --bg-fill
Browse memes from r/memes
wget -O - -q reddit.com/r/memes.json | jq '.data.children[] |.data.url' | xargs feh
Runs
command1
1 out of 10 times
[ $[$RANDOM % 10] = 0 ] && command1 || command2
[ $[$RANDOM % 10] = 0 ] && timeout 5 command1 || command2
[ $[$RANDOM % 10] = 0 ] && cmatrix || clear
nmcli
Connect to a hidden wifi network using macchanger
Change MAC address using Desktop Entry Template
Example .desktop file (~/.local/share/applications
):
Useful Programs
man [program]
- view man pages for programs.apropos
- search the manual page names and descriptions.[program] --help/-h
cat
tr
- translate or delete characters.cut
- remove sections from each line of files.cut -d, -f 2,3 ratings.csv
- output only the 2nd and 3rd columns from ratings.csv file.
less
echo
head
date
- print or set the system date and time.date +%s
- unix timestamp.
time
- run programs and summarize system resource usage.cal
- displays a calendar.cd
- change working directory.cd -
- change to previous working directory.cd ~-
- same thing ascd -
without echoing the path.
tail
pwd
- print name of current/working directory.passwd
- change user password.alias
- list and create aliases.mkdir -p folder/{sub1,sub2}/{sub1,sub2,sub3}
- make directories/subdirectories quickly.chsh
- change login shell.grep
- pattern searching.fdisk
- disk partition utility.cfdisk
- disk partition utitlity.dd
- convert or copy a file, create bootable USBs from ISOs. use cautiously. can destroy data irreversibly. To monitor the progress of an operation, add thestatus=progress
option to the command.wc
- print newline, word and byte counts for files.history
- show history.<space>man man
- don't addman man
command to history.fc
- fix a long command that you messed up.!666
- run 666th command in history.!-n
- refer to the command n lines back.!-1
/!!
- refer to the previous command.sudo !!
- run previous command but appendsudo
at the beginning.[program] !!
- run previous command using [program].
lsusb
- list USB devices.lsblk
- list information about block devices.env
/printenv
- list all environmental variables.free
- display amount of free and used memory in the system.df
- report file system disk space usage.du
- estimate file space usage.du -sh dir/
- check size of dir/ on disk.
fc-list
- list available fonts.timedatectl
- control the system time and date.cat /etc/timezone
- (on Debian) print current timezone.
xprop
- property displayer for X.shred
- overwrite the specified file(s) repeatedly, in order to make it harder for even very expensive hardware probing to recover the data.mount
- mount a filesystem.clear
- clear the terminal screen.locate
- find files by name.updatedb
- creates or updates a database used by locate.find
- search for files in a directory hierarchy.file
- determine file type.
System Monitoring
ps
- report a snapshot of the current processes.ps aux | grep nginx
- search for 'nginx' in ps output.
htop
- interactive process viewer.top
- display Linux processes.cat /proc/loadavg
- load average.uptime
- tell how long the system has been running.w
- see who is logged on and what they are doing.acpi
- shows battery status and other ACPI information.- (upower -i `upower -e | grep 'BAT'`) - battery information.
pidof [program]
- find the process ID of a running program.
System Info
lsb_release -a
- print distribution-specific information.cat /etc/*release
uname -a
- print system information.cat /etc/fstab
- static file system information.
Networking
vim /etc/resolv.conf
- change DNS server.ip
- show / manipulate routing, network devices, interfaces and tunnels.ip addr
- display IP addresses and property information.
Miscellaneous
- Drop into a tty(tty3):
Ctrl + Alt + F3
- Move to different ttys:
Alt + Left/Right
- Mod Keys:
- Mod1 : Left alt
- Mod3 : Right Alt
- Mod4 : Super/Windows