15 Essential Linux Command Line Tricks You Might Have Forgotten

1. Display output as a table – Use column‑formatting options (e.g., -s to specify a delimiter) to render command output like mount or /etc/passwd in neatly aligned columns.

2. Run until success – Wrap a command in a while true loop and redirect both stdout and stderr to /dev/null with > /dev/null 2>&1 to repeat it until it succeeds.

3. Sort processes by memory or CPU usage – Use appropriate options (e.g., ps aux --sort=-%mem or ps aux --sort=-%cpu) and display the results as illustrated in the accompanying screenshots.

4. Check your architecture (32‑bit or 64‑bit) – Run uname -m or examine /proc/cpuinfo to determine the system’s bitness.

5. Monitor multiple log files simultaneously – Install and use multitail, which can tail several files with highlighting and filtering.

6. Return to the previous directory – Simply type cd - to jump back to the last visited directory.

7. Turn a non‑interactive shell into an interactive session – Add the necessary initialization lines from ~/.bashrc into ~/.bash_profile.

8. Observe command output continuously – Use watch to run any command repeatedly (e.g., watch df -h) and watch its output change over time.

9. Keep a program running after closing the session – Prefix the command with nohup (e.g., nohup myscript.sh &) to prevent it from being killed when the shell exits; output is saved to nohup.out.

10. Yes/No answer bot – Automate affirmative responses with yes and negative responses with yes | head -n 1 | tr 'y' 'n' (illustrated in the screenshots).

11. Create a file of a specific size – Use dd if=/dev/zero of=sample.bin bs=1M count=10 to generate a 10 MB zero‑filled file.

12. Run the previous command as root – After forgetting to prepend sudo, simply type sudo !! to re‑execute the last command with root privileges.

13. Record your command‑line session – Start script to capture all keystrokes into a typescript file; exit the shell to finish recording.

14. Replace spaces with tabs – Employ tr ' ' '\t' to convert spaces to tab characters in a stream or file.

15. Change case – Use tr 'a‑z' 'A‑Z' to convert text to uppercase.

16. Powerful xargs usage – Pipe lists of arguments (e.g., filenames or URLs) to xargs for batch processing; combine with -i and placeholders ( {}) for more complex commands.

The article concludes by encouraging readers to share additional geeky commands and promises future posts on Linux command‑line tricks.