Linux Commands

A collection of practical Linux command line tricks: create a terminal chat server with nc, sum column values on the

ps aux shows you what is running on your system, but witr goes a step further and tells you why

You’ve got a server refusing to start because something’s already sitting on port 8080, and you need to find what’s

df says your disk is 80% full, but du says you’re barely using half, so one of them is lying,

You’ve been copying files with cp for years, and if you’re moving a 50GB backup or syncing a directory tree

You need a 1GB test file to benchmark your disk, fill a partition to a specific threshold, or simulate a

You deleted a log file mid-session, a running process is still writing to it, and ls shows nothing, but the

You’re running df -h every 30 seconds by hand to watch a disk fill up, typing the same command over

You’ve been running a long rsync job or a Python script on a remote server only to watch it die

Every Linux user eventually runs a command they’d rather not preserve – a curl with a hardcoded password, an export

Ctrl+R and fc let you find, recall, and edit any command from your bash history in seconds, and here’s how

You’ve been retyping the same long commands for years, but sudo !!, !$, ^old^new, and a handful of Bash history