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author | Eelco Dolstra <edolstra@gmail.com> | 2020-12-23 18:33:42 +0100 |
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committer | Eelco Dolstra <edolstra@gmail.com> | 2020-12-23 18:33:42 +0100 |
commit | 5178211e963fa111f84c4881b22cc506d5254fde (patch) | |
tree | 6a0287b912ff7e3f59c05afb0e01c93db411df7a /src | |
parent | 26e502ceb567e48f3eb28fb1848430ab69cb7606 (diff) |
Add 'nix' manpage
Diffstat (limited to 'src')
-rw-r--r-- | src/nix/main.cc | 7 | ||||
-rw-r--r-- | src/nix/nix.md | 119 |
2 files changed, 126 insertions, 0 deletions
diff --git a/src/nix/main.cc b/src/nix/main.cc index afe7cb8d7..b2406fafe 100644 --- a/src/nix/main.cc +++ b/src/nix/main.cc @@ -184,6 +184,13 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs { return "a tool for reproducible and declarative configuration management"; } + + std::string doc() override + { + return + #include "nix.md" + ; + } }; static void showHelp(std::vector<std::string> subcommand) diff --git a/src/nix/nix.md b/src/nix/nix.md new file mode 100644 index 000000000..d10de7c01 --- /dev/null +++ b/src/nix/nix.md @@ -0,0 +1,119 @@ +R""( + +# Examples + +* Create a new flake: + + ```console + # nix flake new hello + # cd hello + ``` + +* Build the flake in the current directory: + + ```console + # nix build + # ./result/bin/hello + Hello, world! + ``` + +* Run the flake in the current directory: + + ```console + # nix run + Hello, world! + ``` + +* Start a development shell for hacking on this flake: + + ```console + # nix develop + # unpackPhase + # cd hello-* + # configurePhase + # buildPhase + # ./hello + Hello, world! + # installPhase + # ../outputs/out/bin/hello + Hello, world! + ``` + +# Description + +Nix is a tool for building software, configurations and other +artifacts in a reproducible and declarative way. For more information, +see the [Nix homepage](https://nixos.org/) or the [Nix +manual](https://nixos.org/manual/nix/stable/). + +# Installables + +Many `nix` subcommands operate on one or more *installables*. These are +command line arguments that represent something that can be built in +the Nix store. Here are the recognised types of installables: + +* **Flake output attributes**: `nixpkgs#hello` + + These have the form *flakeref*[`#`*attrpath*], where *flakeref* is a + flake reference and *attrpath* is an optional attribute path. For + more information on flakes, see [the `nix flake` manual + page](./nix3-flake.md). Flake references are most commonly a flake + identifier in the flake registry (e.g. `nixpkgs`) or a path + (e.g. `/path/to/my-flake` or `.`). + + If *attrpath* is omitted, Nix tries some default values; for most + subcommands, the default is `defaultPackage.`*system* + (e.g. `defaultPackage.x86_64-linux`), but some subcommands have + other defaults. If *attrpath* *is* specified, *attrpath* is + interpreted as relative to one or more prefixes; for most + subcommands, these are `packages.`*system*, + `legacyPackages.*system*` and the empty prefix. Thus, on + `x86_64-linux` `nix build nixpkgs#hello` will try to build the + attributes `packages.x86_64-linux.hello`, + `legacyPackages.x86_64-linux.hello` and `hello`. + +* **Store paths**: `/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10` + + These are paths inside the Nix store, or symlinks that resolve to a + path in the Nix store. + +* **Store derivations**: `/nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv` + + Store derivations are store paths with extension `.drv` and are a + low-level representation of a build-time dependency graph used + internally by Nix. By default, if you pass a store derivation to a + `nix` subcommand, it will operate on the *output paths* of the + derivation. For example, `nix path-info` prints information about + the output paths: + + ```console + # nix path-info --json /nix/store/p7gp6lxdg32h4ka1q398wd9r2zkbbz2v-hello-2.10.drv + [{"path":"/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10",…}] + ``` + + If you want to operate on the store derivation itself, pass the + `--derivation` flag. + +* **Nix attributes**: `--file /path/to/nixpkgs hello` + + When the `-f` / `--file` *path* option is given, installables are + interpreted as attribute paths referencing a value returned by + evaluating the Nix file *path*. + +* **Nix expressions**: `--expr '(import <nixpkgs> {}).hello.overrideDerivation (prev: { name = "my-hello"; })'`. + + When the `--expr` option is given, all installables are interpreted + as Nix expressions. You may need to specify `--impure` if the + expression references impure inputs (such as `<nixpkgs>`). + +For most commands, if no installable is specified, the default is `.`, +i.e. Nix will operate on the default flake output attribute of the +flake in the current directory. + +# Nix stores + +Most `nix` subcommands operate on a *Nix store*. + +TODO: list store types, options + +)"" |