This is a list of linux commands which are not commonly used but
still very good to know.
This is neither a complete list nor a cheat sheet of any kind. This is a
reference for myself and something to show to others if they ask “Why
are you using only the commandline?” again.
Searching through a folder recursively and print every occurance with file name and line number:
grep -rin "SearchText" foldernamer = recursive, i = case insensitive, n = display line numbers
history | grep "sudo"find / -type f -iname "passwd"mat2 --inplace *find . -type f -iname "*.png" -exec mogrify -verbose -format jpg {} \;sudo apt-get install jpegoptim
jpegoptim file.jpg
jpegoptim **/*.jpgsudo apt-get install pngquant
pngquant -v --skip-if-larger -s 1 -f --ext .png filename.pngsudo apt-get install ffmpeg
ffmpeg -i inputfile.mkv -crf 25 -vcodec h264 -acodec aac output.mp4zip -r folder.zip folder/zip is mostly pre-installed. The unzip command needs to be installed with
sudo apt-get install unzipsudo apt-get install pz7ip-full
7z a -m0=lzma2 -mx=9 folder.7z folder/Hint: 7zip is miles better than zip. It converted 14GB of similar text down to 850MB!
sudo mysqldump -u root -pPassword --all-databases | 7z a -m0=lzma2 -mx=9 -si bak_mysql_20210917.xb.7zsudo mysqldump --all-databses | gzip > bak_sql_$(date +\%Y\%m\%d\%H\%M).sql.gzSimple method for non-complex websites with max depth = 5:
wget --recursive --page-requisites --adjust-extension --span-hosts --convert-links --domains example.com --no-parent example.comMore complex method:
wget --recursive --no-parent --convert-links --no-host-directories --execute robots=off --user-agent=Mozilla/5.0 --level=inf --accept '*' --reject="index.html*" --cut-dirs=0 https://example.comcurl -X POST -H "Content-Type: application/json" -d '{"resource":"mywebpage.docx"}' http://example.com/getResourcecurl -u user:password https://example.com/secret_pagecurl -A "Valve/Steam HTTP Client 1.0 (4000)" "https://example.com"First install youtube-dl with
sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl
sudo chmod a+rx /usr/local/bin/youtube-dl
sudo apt-get install ffmepgThen use the following command to download a youtube video
youtube-dl https://www.youtube.com/watch?v=xJoAhrFETbkyoutube-dl -f bestaudio --extract-audio --audio-format aac https://www.youtube.com/watch?v=xJoAhrFETbk --rm-cache-diryoutube-dl -f bestvideo+bestaudio https://www.youtube.com/watch?v=xJoAhrFETbkyoutube-dl -f bestaudio --extract-audio --audio-format aac https://www.youtube.com/playlist?list=xxxxxxxxxxxxxxxxxxxyoutube-dl -f bestaudio --extract-audio --audio-format aac https://www.youtube.com/playlist?list=xxxxxxxxxxxxxxxxxxx --playlist-start 8 --rm-cache-diryt-dlp -f bestaudio --abort-on-error -4 --rate-limit "1M" --sleep-interval 5 --sleep-requests 5 --no-cookies --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36" "https://www.youtube.com/playlist?list=XXXXXXX"To resume a download after an error (e.g. from playlist item 1266) add the following to it:
-I "1266:"You can remove the --abort-on-error flag if you only get
“video not found” errors.
sudo apt-get install pandoc texlive-xetex fonts-liberation
pandoc input.txt --pdf-engine=xelatex -o output.pdffind . -name "*.lua" | xargs wc -lfind . -type f -name "*.lua" | xargs -0 sed -i '' -e 's/Slot = 0/Slot = 3/g'find * -type f -size 1k | xargs -I{} grep -rih {} .Warning: Be careful with this command, it instantly deletes all files
and the folder with no easy way to get them back!
To delete an empty folder use rmdir instead!
rm -r folderTo move all files INSIDE folderA to folderB (end: folderB/test.txt)
mv folderA/* folderBTo move folderA to folderB (end: folderB/folderA/test.txt)
mv folderA folderBTo move all files from folderA to the current directory (end: test.txt)
mv folderA/* .Hint: Moving files copies over SELinux permissions. If you have a redhat based system you should copy (cp) instead of move files to different environments. (Example: Don’t mv a file from home to web folders, it won’t be accessible)
To encrypt a file use
gpg -c backup.zipTo decrypt the file use
gpg -d backup.zip.gpgshopt -s globstarfind /home/user/folder -type f -printf '%T+\t%s\t%p\n' > $(date +\%Y\%m\%d\%H\%M).txtecho "My linux is $(uname -a)"chown -R user:user folderHint: This command needs sudo in most cases.
chmod -R a+rwx folder
# ^ is the same as:
chmod -R 777 folderfor run in {1..100}; do echo $run; doneExample: Start Minecraft Server in the background
screen -Sdm mc java -Xmx4096M -Xms1024M -jar forge-1.16.5-36.2.0.jar noguiExample: Stop a Minecraft server running in a screen called “mc” by sending “stop”
echo "screen -S mc -X stuff 'stop'\`echo -ne '\015'\`" > stop.shscript -c "grep -rin Receive"
aha -s -f typescript > out.htmlExample: you have a linux server (root@example.com) that has an
application running on port 3000 but only locally.
You can access this application by using the following command and then
visiting localhost:9100 in your browser:
ssh -L 9100:localhost:3000 root@example.comThe syntax is
<local_port>:localhost:<remote_port> <user@remote_server> -P <remote_ssh_port>
02 5 * * * mysqldump -u root --all-databases > /root/backups/bak_mysql_$(date +\%Y\%m\%d\%H\%M).sql
02 6 * * * find /root/backups/* -mtime +7 -exec rm {} \;SELinux is “Security Enhaned Linux” which is automatically installed
on redhat based systems (Fedora, RedHat Linux, CentOS, Rocky Linux). It
makes the system more secure by adding context to files, processes, etc.
and checking them before accessing the content.
For more visit https://www.redhat.com/en/topics/linux/what-is-selinux
ls -Zahlsemanage fcontext -a -t httpd_sys_content_t "/web(/.*)?"
restorecon -R -v /websemanage fcontext -d "/web(/.*)?"
restorecon -R /websemanage port -l (| grep http)semanage port -a -t http_port_t -p tcp 82ps Zauxnetstat -Ztulpensemanage boolean -lgetsebool -a | grep ftpdsetsebool -P ftpd_anon_write onaureport -a
grep sealert /var/log/messagesThe following command backups only the important files that are not standard in a gmod server installation, the zip name contains: “bak” for backup, “liquidscprp” is the servername and “20211127” is year+month+day
zip -r bak_liquidscprp_20211127.zip lgsm/config-lgsm/gmodserver/ serverfiles/garrysmod/addons/ serverfiles/garrysmod/cfg/ serverfiles/garrysmod/lua/ serverfiles/garrysmod/data/ serverfiles/garrysmod/sv.db serverfiles/garrysmod/gamemodes/To compress it more you can install 7zip and use that. To install it
sudo apt-get install p7zip-fullThen use the following command to create the same zip file as the example above, just more compressed
7z a -m0=lzma2 -mx=9 bak_liquidscprp_20211127.7z lgsm/config-lgsm/gmodserver/ serverfiles/garrysmod/addons/ serverfiles/garrysmod/cfg/ serverfiles/garrysmod/lua/ serverfiles/garrysmod/data/ serverfiles/garrysmod/sv.db serverfiles/garrysmod/gamemodes/To open the current log file use
less ~/log/console/gmodserver-console.logHere you can scroll with the arrow keys and search for words using the / syntax like this
/texthereTo exit the less command simply press Q.
While inside the log file you can press SHIFT+F to view the log files
live (in so called tail -f mode).
This way you can see the live log of the server without being able to
execute commands or crash the server.
To get out of this live mode press CTRL+C. To then exit the less command
press Q.
ffmpeg is a commandline tool to convert media (audio, video) into different formats, manipulate or compress them, put filters on, etc. .
An example command to convert an mkv file into an mp4 file, scale it down to HD, compress it by value 25, set the framerate to 30, audio/video codec to h264/aac and burn in the subtitles into the video:
ffmpeg -i input.mkv -vf "subtitles=input.mkv,scale=1280:720" -crf 25 -vcodec h264 -acodec aac -r 30 output.mp4For more such commands please visit the according blog post:
https://shira.at/blog/ffmpeg.html
ffmpeg -i inputfile.mp4 -filter_complex \
"[0:v]pad=iw:ih+100:0:(oh-ih)/2+50:color=white, \
drawtext=text='Me coming to my wife's funeral':fontsize=42:x=(w-tw)/2:y=(100-th)/2" \
outputfile.mp4pandoc is a commandline tool to convert text and document formats into each other. An example is to convert a markdown file into a pdf:
pandoc mdinput.txt --pdf-engine=xelatex -o output.pdfor to, for example, convert the markdown txt file into this html file:
pandoc linux_commands.txt -s --toc -M document-css=false -o linux_commands.htmlpandoc can also create powertpoint-like pdf slideshows from
markdown.
For more please visit the according blog post:
https://shira.at/blog/pandoc.html