Learn Perl Scripting for Shell Users: From One-Liners to Automation

Read more: https://www.linuxteck.com/learn-perl-scripting-for-shell-users/

Already comfortable with shell scripting? Perl can be a useful next step for text processing, regex, log analysis, reports, and Linux automation.

This practical guide covers Perl scripts, one-liners, file handling, regex, cron jobs, email reports, and debugging with sysadmin-focused examples.

#Linux #Perl #SysAdmin #Automation #ShellScripting #LinuxTeck

Top 50 Bash Script Basics Interview Questions

50 beginner questions covering shebangs, permissions, script execution, variables, user input, exit codes, and practical code-reading exercises.


Read Part 4 : https://www.linuxteck.com/write-your-first-bash-script/

#LinuxTeck #Linux #Bash #SysAdmin #DevOps

Quick Linux Tip #12

Question: How do I find which process is slowly eating my RAM?

Try: watch -n 5 'ps -eo pid,user,vsz,rss,comm --sort=-rss | head -20'

Info: watch runs the command repeatedly showing memory trends. RSS shows physical memory in KB. If a process's RSS keeps growing, you have a leak.

Examples:
$ watch -n 1 'free -m'
$ smem -tk -s rss # More accurate memory reporting
$ sudo pmap -x 1234 | tail -1 # Detailed memory map

Note: smem is more accurate than ps for shared memory. Install: apt install smem. Monitor over hours to detect slow leaks.

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Build Reliable Linux Storage with RAID

Read the full guide: https://www.linuxteck.com/build-reliable-linux-storage-with-raid/

RAID is more than combining disks. The right RAID level can improve performance, add redundancy, and help keep systems running when a drive fails.

This practical guide covers RAID 0, 1, 5, 6, and 10, along with mdadm commands, RAID monitoring, failed disk replacement, and rebuild management.


#Linux #RAID #LinuxAdmin #SysAdmin #Storage #mdadm #linuxteck

Quick Linux Tip #13


Question: I deleted a log file but the app is still writing to it. Can I recover it?

Try: sudo ls -la /proc/1234/fd/

Info: Linux keeps deleted files on disk while any process has them open. /proc/PID/fd/ shows file descriptors with (deleted) marker for such files. Copy from there to recover.

Examples:

$ sudo lsof +L1 # Find all deleted-but-open files
$ sudo ls -la /proc/$(pgrep nginx)/fd/
$ sudo cp /proc/1234/fd/1 recovered.log

Note: Two steps: identify FD number, then copy. Works only while process runs. Restarting the process = data lost forever.

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DigitalOcean vs Vultr: Which Cloud VPS Wins for Developers in 2026?

Read the full comparison and choose the right platform for your workload : https://www.linuxteck.com/guides/digitalocean-vs-vultr/

DigitalOcean or Vultr? The better choice depends on what you actually need.

DigitalOcean stands out for managed services, strong documentation, and less operational overhead. Vultr brings raw performance, competitive pricing, and wider global reach.

Our comparison breaks down pricing, performance, Kubernetes, security, DDoS protection, managed services, and real-world use cases.



#LinuxTeck #DigitalOcean #Vultr #CloudHosting #Linux #DevOps #CloudComputing #VPS

Kinsta delivers strong performance, managed backups, staging, and 24/7 support, but the $35/month starting price is not for every WordPress site.

Read the full review : https://www.linuxteck.com/guides/kinsta-review/

Our Kinsta Review 2026 looks at where the premium price makes sense and where it does not.


#LinuxTeck #Kinsta #WordPress

Quick Linux Tip #14

Question: How do I make /var/www/site accessible at /home/linuxteck/website too?

Try: sudo mount --bind /var/www/site /home/linuxteck/website

Info: Bind mounts make the same content visible at multiple paths. No copying, no symlinks. Both paths refer to the same underlying files.

Examples:

$ sudo mount --bind /source /destination
$ sudo mount --bind -o ro /etc /backup/etc_ro # Read-only bind
$ sudo umount /home/linuxteck/website

Note: Persist by adding to /etc/fstab: '/var/www/site /home/linuxteck/website none bind 0 0'. Used heavily in containers and chroots.

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Quick Linux Tip #15

Question: How do I delete 100,000 tiny cache files quickly?

Try: time find /tmp/cach -type f -name '*.tmp' -print0 | xargs -0 -n 100 -P 8 rm

Info: -print0 outputs null-separated filenames. -0 tells xargs to expect them. -n 100 batches 100 files per rm call. -P 8 runs 8 parallel processes.

Examples:

$ find /var/log -name '*.gz' -mtime +30 -print0 | xargs -0 -P 4 rm
$ find /data -name '*.raw' -print0 | xargs -0 -P 8 -I {} convert {} {}.jpg
$ find /tmp -type d -empty -print0 | xargs -0 -P 4 rmdir

Note: Use nproc to see CPU count. -n batching avoids 'argument list too long' errors. Massive speedup vs serial deletion.

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Still using netstat?
The Linux ss command is faster, more powerful, and installed by default on most modern distributions.
Learn practical socket monitoring, connection filtering, listening ports, and troubleshooting examples.
📖 https://www.linuxteck.com/ss-command-in-linux/
#Linux #SysAdmin #DevOps #Networking #linuxteck

Quick Linux Tip #16

Question: Why is my repeated SSH connection so slow, and how do I fix it?

Try: cat >> ~/.ssh/config << 'EOF' Host * ControlMaster auto ControlPath ~/.ssh/cm-%r@%h:%p ControlPersist 10m EOF

Info: SSH multiplexing reuses the first connection for subsequent sessions. ControlMaster creates a master socket, ControlPersist keeps it alive for 10 minutes.

Examples:

$ ssh -O check user@server # Verify master exists

$ ssh -O stop user@server # Close master connection

$ ssh -O exit user@server # Force close

Note: Massive speedup for scripts/CI/CD that ssh repeatedly. Second connection was 48x faster in the example above.

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Debian 13.6 Released: 244 Important Fixes Every Linux User Should Know

Debian 13.6 "Trixie" is now available with 120 security advisories and 124 stability fixes, along with important Secure Boot improvements and updates to packages like Apache, Curl, Samba, Python 3.13, QEMU, Wireshark, and more.

If you're running Debian in production or planning an upgrade, this release is well worth reviewing.

Read the full breakdown:
https://www.linuxteck.com/debian-13-6-brings-244-important-fixes-to-linux/

#Linux #Debian #Debian13 #OpenSource #LinuxAdmin #SysAdmin #CyberSecurity #LinuxNews #LinuxTeck

Quick Linux Tip #17

Question: Are my source and backup directories truly identical?

Try: diff <(cd /source && find . -type f -exec md5sum {} + | sort) <(cd /backup && find . -type f -exec md5sum {} + | sort)

Info: Combines find, md5sum, sort, and process substitution to compare directories by content, not just names. Detects even single-byte modifications.

Examples:

$ rsync -avnc /source/ /destination/ # Dry-run checksum check
$ find /a -type f | xargs sha256sum | sort > /tmp/a.sums
$ sha256sum -c backup.sums # Verify files against saved hashes

Note: Use sha256sum for security-critical checks. rsync -c does similar but modifies filesystem. Perfect for backup verification.

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Linux chgrp Command Made Easy | Change Group Ownership Like a Pro


Managing group ownership is a key Linux administration skill. This practical guide explains the chgrp command with real-world examples, useful options, common mistakes to avoid, and best practices for beginners and experienced sysadmins alike.

Read the complete guide: https://www.linuxteck.com/chgrp-command-in-linux-made-easy/

#Linux #LinuxAdmin #SysAdmin #DevOps #OpenSource #LinuxCommands #CommandLine #LinuxTutorial #LinuxTips #linuxteck

Quick Linux Tip #18

Question: How do I automatically reload nginx when its config changes?

Try: sudo inotifywait -m -e modify /etc/nginx/nginx.conf

Info: Monitors filesystem events using the inotify kernel API; -m keeps it running in monitor mode.

Examples:

$ inotifywait -m -e modify /etc/nginx/nginx.conf | while read; do systemctl reload nginx; done

$ inotifywait -m -r -e create /var/incoming | while read path event file; do process "$file"; done

$ inotifywait -m -e close_write src/ | while read; do npm run build; done

Note: Install: sudo apt install inotify-tools. Common events: modify, create, delete, close_write. Use -r for recursive directory watching.

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Quick Linux Tip #19

Question: How do I extract just the source IPs from active connections?

Try: ss -tn state established | awk 'NR>1 {split($3,a,":"); print a[1]}' | sort -u

Info: First run ss to see raw output, then use awk to parse. split($4,a,":") splits 'IP:PORT' into array a. NR>1 skips the header line.

Examples:

$ ip -4 addr | awk '/inet / && !/127.0/ {print $2}' | cut -d/ -f1

$ netstat -tn | awk 'NR>2 {split($4,a,":"); print a[1]}' | sort -u

$ cat access.log | awk '{print $1}' | sort -u # Unique visitor IPs

Note: awk is a full text-processing language. $N is Nth column, NR is line number, split() breaks strings into arrays.

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Understanding Linux Special Permissions doesn't have to be difficult.
This guide explains SUID, SGID, and Sticky Bit with practical examples, chmod syntax, security tips, and real-world use cases for beginners and Linux administrators.
📖 https://www.linuxteck.com/special-permissions-in-linux/
#Linux #OpenSource #DevOps #SysAdmin #linuxteck

Learn Python Scripting for Shell Users
Already know Bash?
This guide shows how to transition from Shell scripting to Python with practical Linux examples, automation tips, Bash vs Python comparisons, and beginner-friendly explanations.
Read more:
https://www.linuxteck.com/learn-python-for-shell-users-part/
#Linux #Python #ShellScripting #Automation #linuxteck

Quick Linux Tip #20

Question: How do I write a script that cleans up its temp files even on errors?

Try: TMPFILE=$(mktemp) && trap 'rm -f "$TMPFILE"' EXIT INT TERM

Info: mktemp creates a secure, unique file; trap catches signals like exit or Ctrl+C to guarantee cleanup.

Examples:

$ TMPDIR=$(mktemp -d) # Secure temp directory

$ trap 'rm -rf "$TMPDIR"' EXIT

$ mktemp -t script-XXXXXX.log # Custom prefix

Note: Prevents dangling files during unexpected script crashes. Permissions default to 600 (owner-only), preventing local information leaks.

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How to Choose the Right VPS Hosting (Without Regretting It Later)

Choosing a VPS isn't just about CPU, RAM, or the lowest monthly price. The right decision depends on your workload, storage, network quality, scalability, backups, and long-term reliability.
This guide explains what really matters before you buy your next VPS and helps you avoid common mistakes that lead to expensive migrations later.
👉 Read the complete guide:
https://www.linuxteck.com/how-to-choose-vps-hosting/
#LinuxTeck #Linux #VPS #WebHosting #CloudHosting #SysAdmin #DevOps #LinuxServer #Hosting

Every new file and directory in Linux starts with default permissions—and umask is what decides them.
Learn how to:
• Calculate permissions
• Configure umask permanently
• Improve Linux security
• Avoid common permission mistakes
📖 https://www.linuxteck.com/umask-command-in-linux/
#Linux #SysAdmin #DevOps #LinuxTeck