Linux command
nix-eval 命令
文本
复制后可按需替换文件名、目录或参数。
常用示例
Evaluate expression
nix eval --expr "[1 + 1]"
Evaluate from flake
nix eval [.#packages.x86_64-linux.default]
Evaluate and apply function
nix eval --apply [builtins.attrNames] --expr "{a=1; b=2;}"
Output as JSON
nix eval --json --expr "[{a = 1;}]"
Evaluate file
nix eval -f [file.nix]
Raw output
nix eval --raw --expr "\"hello\""
说明
nix eval evaluates Nix expressions. It outputs the evaluated value. The tool inspects Nix values. Useful for debugging and querying.
参数
- --expr _EXPR_
- Nix expression.
- --json
- Output as JSON.
- --raw
- Raw string output.
- --apply _FUNC_
- Apply function to result.
- --help
- Display help information.
FAQ
What is the nix-eval command used for?
nix eval evaluates Nix expressions. It outputs the evaluated value. The tool inspects Nix values. Useful for debugging and querying.
How do I run a basic nix-eval example?
Run `nix eval --expr "[1 + 1]"` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does --expr _EXPR_ do in nix-eval?
Nix expression.