Tools

Compute and verify SHA checksums. Ships with Perl on macOS and Linux.

Command-line shell for SQLite databases. Preinstalled on macOS; apt install sqlite3 on Linux.

PostgreSQL interactive terminal, used non-interactively for one-shot queries and scripts.

Run a command with a time limit. Part of GNU coreutils: built into Linux, 'gtimeout' on macOS after brew install coreutils.

PDF text extraction, page info, and PDF → PNG rendering. The reliable way to read PDFs from a shell.

Screenshot or print any web page (local file or URL) to PNG/PDF with the browser you already have.