💡 TIP: On a Linux system using bash, you can compare text strings without worrying about upper or lowercase by using the ,, (lowercase) or ^^ (uppercase) parameter expansion modifiers e.g. EDITION=CommUNITY if [[ ${EDITION,,} = community ]]; then echo "Community" fi ${EDITION,,} converts the value to lowercase. #ZikTIPs #bash #scripting #linuxtips #techtips #feditips #Linux #opensource

💡 On a Linux system using bash, you can case insensitively compare text by using ,, (lowercase) or ^^ (uppercase) parameter expansion modifiers e.g.

EDITION=CommUNITY
if [[ ${EDITION,,} = community ]]; then
echo "yes"
fi
${EDITION,,} converts value to lowercase
#ZikTIPs #techtips #Linux #opensource

TIP: Calculate the number of days since a given date (e.g. 30 June 2025) on a Linux system: echo $(( ( $(date +%s) - $(date -d "2025-06-30" +%s) ) / 86400 )) #ZikTIPS

💡Calculate the number of days since a given date (e.g. 30 June 2025) on a Linux system:

echo $(( ( $(date +%s) - $(date -d "2025-06-30" +%s) ) / 86400 ))

@opensuse.org @fedora.fosstodon.org.ap.brid.gy @debian.bsky.social
#ZikTIPS #Linuxtips #LinuxTechTips #Linux #FOSS #Opensource

Image with a QR code and text showing the TIP and usage

💡Making a presentation? Add a slick QR code using the Linux command line:

1️⃣ Save your info:
printf "Name: Zik Joseph\nBlog: zikusooka.com/n%22 > my_contacts.txt

2️⃣ Generate QR:
qrencode -o zik.png -r my_contacts.txt

Drop zik.png into your slides. Easy!
#ZikTIPS #Linux #FOSS #TechTips #OpenSource

Linux terminal output showing Fedora and Red Hat security advisories, including package names, types, severity, and issue dates.

💡Use the following command line to list of security advisories on a Fedora and RedHat based Linux systems #ZikTIPs #LinuxTips #LinuxTechTips #Linux #Opensource
@fedora.fosstodon.org.ap.brid.gy

sudo dnf advisory list

A screenshot showing this Linux tip on how to Record audio from a microphone on a Linux system using gstreamer

💡Record audio from a microphone on a Linux system using gstreamer @fedora.fosstodon.org.ap.brid.gy @opensuse.org

gst-launch-1.0 alsasrc ! audioconvert ! lamemp3enc ! filesink location=recorded.mp3

#ZikTIPs #pipewire #pulseaudio #techtips #Linuxtips #LinuxTechTips #Linux #Opensource

Image displaying text of above Linux tip

💡To create a file with a specific access & modification timestamp in #Linux

touch -t [FILE] e.g. March 10 2025 9AM
touch -t 202503100900 mytalk.txt

To verify: stat -c %x%y mytalk.txt
@fedora.fosstodon.org.ap.brid.gy @opensuse.bsky.social
#ZikTIPs #Linuxtips #LinuxTechTips #Linux #Opensource

An image showing a screenshot of a Linux terminal with the mentioned tip command and output

💡You can simultaneously query multiple #DNS records using dig in #Linux:

dig OPTIONS @SERVER -f FILE e.g.
dig +nocmd +noquestion +nostats +nocomments @8.8.8.8 -f mydomains.txt

cat mydomains.txt
example.com A
example.net MX
example.org NS

#ZikTIPS #CLI #Opensource

A screenshot image of a Linux terminal showing the output of the command "lslogins"

💡 To display a full list of known users on a Linux system, use the following command @fedora.fosstodon.org.ap.brid.gy @opensuse.bsky.social @ubuntu-ls.bsky.social

lslogins

#ZikTIPS #Sysadmin #CLI #Fedora #OpenSUSE #Linux #opensource #Tips

💡To display the DHCP IPv4 options assigned to a Linux client, use the following command line #ZikTIPs #CLI #Networking #sysadmins #Linux #OpenSource
nmcli -f DHCP4 device show "$INTERFACE"
e.g.
nmcli -f DHCP4 device show eth0

Screenshot of a Linux terminal showing command to quickly identify the ports that a specific service is listening on within a Linux system.

💡Use the 'lsof' command to quickly identify the ports that a specific service is listening on within a Linux system @fedoraproject.org.web.brid.gy @opensuse.bsky.social @ubuntu-ls.bsky.social
SERVICE=sshd;  lsof  -i  -P  -n  | grep  $SERVICE  |  awk  '/LISTEN/  {print  $9}'  |  uniq

#ZikTIPs #Linux