Tools › Cheat sheets
Command cheat sheets
38 quick references for the commands sysadmins and developers look up every day. Click a command to copy it; risky commands are clearly marked.
🐧 Linux & Shell
🐚
BashShell shortcuts, redirection, variables and scripting basics.
🔎
grepSearch text and files with patterns.
🔍
findSearch for files by name, size, age and more.
✂️
sedSearch, replace and edit text streams from the command line.
🧮
awkProcess columns and fields in text and logs.
📦
tarCreate, extract and inspect tar archives.
📝
VimSurvive and thrive in the Vim editor.
🪟
tmuxTerminal sessions, windows and panes that survive disconnects.
🔐
chmod permissions755, 644, 600 and 777 explained.
🛠️ System Administration
⚙️
systemctlStart, stop, enable and inspect systemd services.
📜
journalctlRead and filter systemd logs.
📦
aptInstall, update and remove packages on Debian and Ubuntu.
🎩
dnf / yumInstall, update and query packages on Fedora, RHEL, Rocky and Alma.
👥
Users & groupsCreate users, manage groups and set ownership.
📊
Processes & performanceInspect, signal and tune running processes.
💽
Disks & storageCheck space, mount filesystems and inspect devices.
🔄
rsyncCopy and synchronise files locally and over SSH.
⏱️
Cron expressionsCopy-paste cron schedules explained.
🔒 Networking & Security
🔑
SSHConnect, copy files, create keys and tunnel traffic.
🌐
curlMake HTTP requests, send data and debug APIs.
🛰️
Linux networkingip, ss, ping, dig and friends for diagnosing connectivity.
🛡️
ufwManage the Ubuntu firewall with simple commands.
🔐
OpenSSLKeys, certificates, CSRs and TLS checks.
🔒
Certbot (Let's Encrypt)Get and renew free TLS certificates.
🌐
Subnet / CIDRMasks and host counts from /8 to /30.
🧱
iptablesList, add and delete Linux firewall rules, plus NAT.
🐳 Containers & DevOps
🌿
GitEveryday Git commands, from first commit to undoing mistakes.
🐳
DockerContainers, images, cleanup and Docker Compose.
☸️
kubectlInspect and manage Kubernetes workloads from the command line.
🅰️
AnsibleRun ad-hoc commands, playbooks, vaults and roles.
🏗️
TerraformPlan, apply and manage infrastructure state.
🗄️ Web Servers & Databases
🚦
nginxTest, reload and configure the nginx web server.
🐘
PostgreSQLpsql meta-commands, backups, roles and diagnostics.
🐬
MySQL / MariaDBClient commands, backups, users and diagnostics.
🔴
Redisredis-cli commands for keys, data types, memory and diagnostics.