28 Essential Unix/Linux Command‑Line Tools Every Sysadmin Should Know

dstat & sar

iostat, vmstat, ifstat combined into a single tool for monitoring system performance; the original author referenced it in a performance tuning guide.

Official site: http://dag.wieers.com/rpm/packages/dstat/

You can use it like this:

alias dstat='dstat -cdlmnpsy'

slurm

A tool for viewing network traffic.

Official site: Simple Linux Utility for Resource Management

vim & emacs

True programmers' text editors.

screen, dtach, tmux, byobu

Screen multiplexes a physical terminal across multiple processes, allowing multiple windows within a single SSH/Telnet session. See IBM DeveloperWorks article "Using screen to manage remote sessions".

dtach simulates screen's detach feature, letting you attach to various sessions.

tmux is an excellent terminal multiplexer from OpenBSD (BSD license) with pane splitting, free movement, copy‑paste across buffers, search, and automatic reattachment after disconnection.

byobu is an Ubuntu‑developed wrapper around screen (now based on tmux) that provides a more user‑friendly interface via the byobu‑tmux front‑end.

multitail

Multitail monitors multiple log files simultaneously, displaying each in its own pane, with features like log statistics, merging, filtering, and split‑screen.

Official site: http://www.vanheusden.com/multitail/

tpp

A terminal‑based PowerPoint‑style presentation tool; using it at a conference makes you look like a true geek.

Official site: http://www.ngolde.de/tpp.html

xargs & parallel

xargs

executes commands from standard input and offers basic parallelism. GNU parallel provides multi‑core and distributed execution, requiring parallel, ssh, and rsync on both local and remote machines.

duplicity & rsyncrypto

Duplicity performs efficient encrypted backups using the rsync algorithm, supporting encrypted directories and remote or local storage.

rsyncrypto combines rsync with encryption; see the author's article on the rsync core algorithm for details.

nethack & slash’em

NetHack is a classic 20‑year‑old rogue‑like game with deep rules and endless variety. Slash’EM is a well‑known variant based on NetHack.

lftp

Command‑line FTP client for incremental website backups and mirroring, similar to rsync.

ack

A Perl‑based grep alternative designed for programmers, offering highlighted matches, recursive search, and file‑type filtering.

calcurse & remind + wyrd

Calcurse is a terminal calendar and task manager; remind + wyrd provide similar functionality.

newsbeuter & rsstail

Command‑line RSS readers.

powertop

Intel’s tool for identifying power‑hungry processes on laptops, helping users reduce energy consumption.

htop & iotop

Interactive monitors for processes, memory, and I/O load.

ttyrec & ipbt

ttyrec

records terminal sessions; ipbt replays those recordings. Similar tools include Shelr and termrec.

rsyn

Classic SSH‑based file synchronization tool (core algorithm).

mtr

Traceroute 2.0 combines traceroute and ping for network diagnostics.

socat & netpipes

socat

(“socket cat”) is a powerful netcat replacement; netpipes offers similar socket operations for shell scripts.

iftop & iptraf

Tools for monitoring current network traffic.

siege & tsung

Siege

stress‑tests web sites with concurrent users, measuring response times. Tsung is a multi‑protocol load tester (HTTP, WebDAV, PostgreSQL, MySQL, LDAP, XMPP/Jabber) supporting cookies, authentication, SSL, and distributed testing.

ledger

Command‑line accounting tool.

rtorrent & aria2

rTorrent

is a lightweight, ncurses‑based BitTorrent client suitable for remote use via screen or ssh. aria2 is a high‑speed downloader supporting segmented downloads, resume, HTTP/HTTPS, FTP, and BitTorrent.

ttytter & earthquake

ttytter

is a Perl CLI for posting to Twitter, supporting Chinese. earthquake is another command‑line Twitter client.

vifm & ranger

vifm

is a ncurses‑based, DOS‑style file manager operated via keyboard. ranger is a Python file manager with Vim‑style key bindings, multi‑column view, tabs, and real‑time previews.

cowsay & sl

cowsay

displays ASCII art speech bubbles; sl humorously shows a train animation when you mistype ls.

linuxlogo

Displays various Linux distribution logos (install with sudo apt‑get install linuxlogo and run linuxlogo -L).

End of article.