Basic Documents Great a file called name.ms, with the following content: 1.TL 2Groff-Time 3.AU 4Ghost 5.NH 6How to Format Groff Documents. 7.PP 8Groff needs two new lines to show a new paragraph. Then make a pdf from the document with: groff -ems name.ms -Tpdf > name.pdf The commands must be placed at the start of a …

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A hard link is one file which exists in multiple locations. Each file has an ID, which is kept on the hard disk's partition. Each hard link has the same ID, because they are the same file. This ID is called the 'inode'. Create a file, and a hard link: 1fortune > $file_1 2mkdir -p x/y/z/ 3ln $file_1 x/y/z/$file_2 Have a …

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Convert jpg to png. 1magick image.jpg image.png 1magick image.jpg -quality 50 image.jpg 'Quality' must be from 1 to 100. 1magick -resize 50% image.jpg image2.jpg Resizing only changes jpegs. Change a png with: 1magick input.png png8:out.png Invert Colours 1magick input.jpg output.jpg -negate Make Images Smaller 1magick …

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Download the Database Download the csv data, and separate the ipv4 data from the ipv6. 1curl -Lo ips.zip 'https://www.kaggle.com/api/v1/datasets/download/ipinfo/ipinfo-country-asn' 2unzip -p ips.zip country_asn.csv | csv2rec | recsel -e "start_ip ~ '.'" > ipv4.rec 3unzip -p ips.zip country_asn.csv | csv2rec | recsel …

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Intro This is a basic Linux firewall program. Look at your firewalls: 1iptables -L We see the output of input, output and forwarding rules. Forward I don't need any forwarding, so I'm going to drop all forwarding: 1iptables -P FORWARD DROP Input Let's 'A'dd, or 'A'ppend a rule with -A. Let's drop all input from a …

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Jenkins on Void Jenkins is janky. Start Start the service file. 1su root 2ln -s /etc/sv/jenkins /var/service 3sv start jenkins Then visit the web interface with $BROWSER localhost:8080. If it's not working, try running the command from the run file the first time: 1chpst -u jenkins java -jar /opt/jenkins/jenkins.war …

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See a running log of all system messages: 1journalctl -f Or just one user: 1journalctl --user -f Or just one unit (sshd): 1journalctl -f -u sshd Find errors since November 1journalctl --since=2018-11-01 --grep="EXT4-fs error" Limit size to 2G. 1journalctl --vacuum-size=2G Log the fact that you've installed your own …

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asciiquarium cbonsai -lim "$(fortune)" 1cow=$(cowsay -l | sort -R | head -1) 2fortune -s | figlet | cowsay -nf $cow | lolcat Watch the Collatz Conjecture collapse: 1x="$(du -sc ~/.cache | tr -d '[:alpha:]' | tail -1)" 2until [ "$x" -eq "1" ]; do 3 test "$(( x % 2 ))" -eq 0 && x=$(( x / 2 )) || \ 4 x=$(( x * 3 + 1 )) 5 …

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Kernel modules live in lib/modules/$(uname -r) Change Load them with 1modprobe ath9k Or remove one with 1modprove uvcvideo The PC's irritating speaker beep can be really annoying. Disable it with: 1modprobe -r pcspeaker Permanently disable a module by blacklisting it in /etc/modprobe.d: 1echo 'blacklist pcspkr' > …

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System-Wide Capslock and Escape Swap This works everywhere, including in a bare-ass tty. Select a keymap, and create a new custom map. 1su root 2ls /usr/share/kbd/keymaps/i386/qwerty/ 3 4basemap=/usr/share/kbd/keymaps/i386/qwerty/pl1.map.gz 5newmap=/usr/share/kbd/keymaps/custom.map.gz 6 7gunzip -c $basemap | \ 8 sed …

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