Linux, Python, Security, and Open Source Software TIPS

Working with systemd Timers @opensuse #Linuxhttps://documentation.suse.com/sle-micro/6.0/html/Micro-systemd-working-with-timers/index.html

💡️To run a Linux systemd service every day at midnight and every three hours thereafter, use the following stanza in your systemd timer #ZikTIPS #Systemd #Sysadmin #CLI #Linux #opensource…[Timer]OnCalendar=*-*-* 00/3:00:00 …Happy #SysAdminDay

💡Display a list of 10 files with the largest size in your home directory #ZikTIPs #CLI #Linux #Opensource @fedora @opensuse @debianfind $HOME -type f -exec ls -lh {} \; | sort -k 5 -rh | head -n 10

As part of my recent talk at the #oSC24 conference in Nuremberg, Germany, I wrote a simple install script for Icinga2 / IcingaWeb on OpenSUSE Leap 15.6 Linux @icinga @opensuse https://github.com/zikusooka/OpenSUSE#Icinga #MonitoringLove #Linux #OpenSource

I have uploaded the latest image of Jambula OS, a Linux based embedded operating system for the Raspberry Pi 5,Feel free to download and try it out at: https://github.com/zikusooka/Jambula-OS #raspberrypi #raspberrypi5 #embedded #DIY #arm #Linux #opensource

I am presenting at the OpenSUSE conference 2024 taking place in Nuremberg, Germany @OpenSUSE @fedora #oSC24 #Linux #Opensource https://streaming.media.ccc.de/osc24

💡 Use the following Linux command to display the expiry date of an SSL certificate:CERT_FILE=/etc/ssl/cert.pem; openssl x509 -in ${CERT_FILE} -text -noout | awk -F": " '/Not After/ {print $2}'#ZikTIPs #OpenSSL #SSL #Encryption #sysadmin #Fedora #Debian #OpenSUSE #Linux

Display the environment variables used by a given process in LinuxPID=5801; strings /proc/$PID/environ#ZikTIPs #CLI #Linux #Opensource

Good news, Jambula OS now supports the latest Raspberry Pi 5 board! Download the image from:https://github.com/zikusooka/Jambula-OSJambula OS is a custom Linux distribution used primarily on embedded and SoC based devices such as the Raspberry Pi. #raspberrypi #raspberrypi5 #JambulaOS #DIY #Linux #opensource

💡 Use the Linux command line to get a JSON-formatted output showing partition, size, path, and other information for a given disk model #ZikTIPs #CLI #SysAdmin #Fedora #Opensuse #Linux #Opensourcesudo /usr/sbin/parted -l -j | jq -r '.disk | select(.model=="ATA SanDisk Z400s 2.")'

💡 Get the model of your Raspberry Pi using the following simple command #ZikTIPS #RaspberryPi #DIY #CLI #Linux #Opensource cat /sys/firmware/devicetree/base/model

💡 Want to know what stuff is embedded in that QR or Bar code?Use the following command in Linux to decode and read a bar-coded imagezbarimg -v [IMAGE] e.g. zbarimg -v signal.pngNOTE: zbarimg is part of the zbar package#ZikTIPS #Systemd #Sysadmin #CLI #Fedora #Debian #Linux

💡 Are you having difficulty wrapping your head around the OnCalendar pattern in systemd timers? Simply use the command:systemd-analyze calendar "[TIME-PATTERN]" e.g.systemd-analyze calendar "hourly"#ZikTIPS #Systemd #Sysadmin #CLI #Fedora #Linux #Opensource

💡 Use the following command to find out which key has been pressed in Linux#ZikTIPS #CLI #Fedora #Linux #Opensourcesudo showkey

Alternatives to popular CLI tools: uptime #CLI #Linux #opensource https://www.linuxlinks.com/alternatives-popular-cli-tools-uptime/

The upstream xz repository and the xz tarballs have been backdoored. Red Hat issues urgent security alert for @fedora Linux 40 & Fedora Rawhide users #security #cybersecurity #infosec #xz #Fedora #linux #opensourcehttps://www.openwall.com/lists/oss-security/2024/03/29/4

💡Use the command line in Linux to mount & un-mount partitions located in an image generated by a tool such as dd #ZikTIPS #Fedora #Debian #CLI #Linux #Embedded #opensource sudo losetup -fP –show JambulaOS.imgsudo mount -o loop /dev/loop21pX /mnt(where X = 1, 2 …)sudo umount /mntsudo losetup -D JambulaOS.img

Happy to release the latest version of Jambula OS, a custom Linux distribution used primarily on embedded and SoC devices such as the Raspberry Pi. Download it at: https://github.com/zikusooka/Jambula-OS#JambulaOS #JambulaTV #RaspberryPi #Linux #OpenSource

💡️Find the version of a Linux kernel source tree that you have unpacked#ZikTIPS #CLI #Fedora #Linux cd [linux-source-tree]make kernelversion

Use the Linux command line to get the number of days left before that all important day e.g. an upcoming conference @fedora @climagic @Linux @debian #ZikTIPS #CLI #Fedora #Linux #OpensourceFUTURE_DATE="2024-03-31"; echo $(( ($(date -d $FUTURE_DATE +'%s')-$(date +'%s')) / 86400))NOTE: You can also use it in reverse e.g. calculate number of days you have been on earth