A collection of short, practical Linux tips I reach for during everyday work — from listing files more clearly to deleting them safely, searching faster, and cleaning up Docker. Keep this page handy as a quick reference.

Listing Files

List files vertically with ls -1

We usually list the files in a directory with ls. But when there are many files, the output wraps across the line and becomes hard to read. Add the -1 option to list files one per line, which is easier to scan.

ls -1

Group files by extension with ls -lX

By default, ls -l orders files in a way that mixes extensions together. Add the -X option to group files by extension.

ls -lX

View file info with getfacl

We usually use ls -l to view file ownership and permissions, but its output is hard to read. Try getfacl instead — it presents the same information in a much clearer layout.

getfacl file.txt

Working with File Contents

Remove empty lines with grep

Use grep with the . pattern to strip empty lines from a file — . matches any line that contains at least one character.

grep . input.txt

Deleting Files Safely

Confirm each deletion with rm -i

Sometimes you need to delete most files in a directory but keep a few. Instead of crafting a fiddly wildcard, add the -i option: rm will ask for confirmation before removing each item, so you delete exactly what you intend to.

rm -i *

Preview a command with echo before running rm

Prefix a command with echo to preview what it would do without actually running it. This is perfect for double-checking which files a wildcard will match before you delete them:

echo rm -rf *

Once you’re happy with the list, drop the echo and run it for real. Very handy. 😁

Finding Files Faster

Stop searching early with find -quit

By default, find keeps searching through every file that matches your pattern. Add -quit to stop as soon as it finds the first match — great when you just need to know which directory a log file lives in.

find / -name "app.log" -print -quit

Date and Time

Get the day of the year with date

The date command shows the current time. To get the day of the year (1–366), use the '+%j' format.

date '+%j'

Fix a server’s clock after downtime

When a server is down for a while and comes back up, its clock can drift out of sync with real time. Fetch the current time from a reliable source and set it:

CURRENT=$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z

sudo date -s "$CURRENT"

Docker

Remove all exited containers

When working with Docker you’ll often want to clear out every container in the exited state, instead of removing them one by one with docker rm <container-id>. Do it in one line:

docker rm $(docker ps -a -f status=exited -q)

Wrapping Up

That’s the cheatsheet for now. Each of these is a small trick on its own, but together they save real time over a day of work at the terminal. Bookmark this page and come back whenever you need a quick reminder.