The right command, explained.
Search real Terminal & command-line solutions for macOS, Windows and Linux — each with a direct answer, the exact command, its risks and how to undo it.
Use codesign and spctl to see whether a macOS app's code signature is valid, intact and acceptable to Gatekeeper.
Use PowerShell to group files by SHA256 and confirm identical copies before you delete anything.
Work out whether a file is held open by a program, owned by a dead account, or sitting behind a path longer than 260 characters — then delete it with PowerShell, takeown/icacls and robocopy on Windows.
Popular solutions
Kill and auto-restart explorer.exe — the classic repair for a dead Start menu, unresponsive taskbar, or glitchy icons.
Send a normal termination signal to one specific process, and escalate to a forced kill only if it refuses to quit.
Inspect any systemd unit's loaded/enabled state, active state, main PID, and its most recent log lines in one command.
Use the classic ps aux command to list every process on the system with owner, CPU, memory, and command columns.
Enable a systemd service to start at boot and start it immediately with one command.
Restart a systemd service correctly: full restart, config-only reload, or restart-only-if-running.