15 Essential Linux Command‑Line Tricks to Boost Your Productivity

Linux users know that the command line is a powerful tool for automating repetitive tasks and increasing efficiency. The following fifteen tips demonstrate concise commands and shortcuts that can be immediately applied in everyday workflows.

1. Quickly empty a file

The shortest way to truncate a file is: $ > access.log Other common methods include:

: > access.log

true > access.log

cat /dev/null > access.log

echo -n "" > access.log

echo > access.log

truncate -s 0 access.log

The built‑in : command is a no‑op; it writes nothing, effectively overwriting the file with empty content.

2. Generate a large file quickly

Use dd to create a test file of a specific size, e.g., 1 GB:

$ dd if=/dev/zero of=file.img bs=1M count=1024

3. Securely erase a disk

Overwrite a whole disk with random data using dd and /dev/urandom: $ dd if=/dev/urandom of=/dev/sda This method provides a simple way to securely delete all data on the target drive.

4. Create a bootable system USB

Write an ISO image directly to a USB device (or any block device) with a single command:

$ dd if=ubuntu-server-amd64.iso of=/dev/sdb

5. Show a process’s elapsed time

Instead of the generic ps aux, specify the -o option to display only the desired fields: $ ps -p 10167 -o etimes,etime Use etime to see that the process has been running for 19 days.

6. Monitor logs in real time

Tail a log file continuously: $ tail -f test.log Stop automatically when a line containing "Failed" appears:

$ tail -f test.log | sed '/Failed/ q'

7. Convert timestamps

Convert a Unix timestamp to a readable date: $ date -d@1234567890 +"%Y-%m-%d %H:%M:%S" Show the current timestamp:

$ date +%s

8. Measure program execution time

Use the time command: $ time ./test The output shows real (wall‑clock time), user (CPU time in user space), and sys (CPU time in kernel space). Differences arise when the program blocks (e.g., sleep, I/O) or runs on multiple CPUs.

9. View ASCII table

Display the ASCII reference directly in the terminal:

$ man ascii

10. Delete files with garbled names

Find a file by its inode number and remove it:

$ ls -i

$ find . -inum 132395 -exec rm {} \;

11. Get your public IP address

Query an external service with curl:

$ curl ip.sb

$ curl ifconfig.me

12. Batch download web resources

Recursively download all PDF files from a site using wget:

$ wget -r -nd -np --accept=pdf http://fast.dpdk.org/doc/pdf-guides/

13. History command shortcuts

!!

– repeat the previous command. !N – repeat command number N from history. !pw – repeat the most recent command starting with pw. !$ – expand to the last argument of the previous command.

14. Quickly search command history

Press Ctrl+r and type a keyword to perform an incremental reverse search through the history.

15. Prevent a command from being saved in history

Prefix the command with a space; Bash will skip recording it, which is useful for commands containing sensitive information.