DOT-Files/Gentoo/gentooamd/home/user/.tldrc/tldr/pages/common/nix-eval.md

nix eval

Evaluate a Nix expression and print the result to stdout. More information: https://nix.dev/manual/nix/stable/command-ref/new-cli/nix3-eval.html.

• Evaluate Nix flake attributes in the current directory:

nix eval .#{{attributes}}

• Evaluate a given Nix expression:

nix eval --expr '{{your_expression}}'

• Evaluate a Nix expression from a specified file:

nix eval --file {{path/to/file}}

• Print the store path of the specified package from nixpkgs:

nix eval {{nixpkgs#pkg}} --raw

• Evaluate attributes from a flake directly from GitHub:

nix eval {{github:owner/repo#attributes}}

• Evaluate a given lambda function passing the specified package as argument:

nix eval {{nixpkgs#pkg}} --apply '{{lambda_function}}'