Thought I would share some commands I genuinely use all the time. Not the usual “top 10 linux commands” listicle stuff — these are the ones that have actually saved me time repeatedly.
Find what is eating your disk space (human-readable, sorted):
du -h --max-depth=1 /var | sort -hr | head -20
Watch a log file with highlighting for errors:
tail -f /var/log/syslog | grep --color -E "error|warn|fail|$"
The |$ trick highlights your keywords while still showing all lines.
Quick port check without installing nmap:
: </dev/tcp/192.168.1.1/22 && echo open || echo closed
Pure bash, no extra tools needed.
Find files modified in the last hour (great for debugging):
find /etc -mmin -60 -type f
Kill everything on a specific port:
fuser -k 8080/tcp
Quick HTTP server from any directory:
python3 -m http.server 8000
Everyone knows this one, but I still see people installing nginx for quick file transfers.
Check SSL cert expiry from the command line:
echo | openssl s_client -servername example.com -connect example.com:443 2>/dev/null | openssl x509 -noout -dates
What are your go-to one-liners? Always looking to add to my toolkit.
I use
newa lot. Just an ugly function I wrote to show the newest files in a directory, but handy for those “what the hell was that file I was just working on named?” moments. Defaults to the newest 15 if not given an arg.new () { if [[ $# -ne 1 ]]; then num=15; else num="$1"; fi; num=$((num+1)); /usr/bin/ls -lth | head -"$num" }