From 2da6a424486e16b4b30e448a15a9b4a608df602d Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Thu, 4 May 2017 14:16:26 +0200 Subject: [PATCH] nix dump-path: Add This is primarily useful for extracting NARs from other stores (like binary caches), which "nix-store --dump" cannot do. --- src/nix/command.cc | 10 ++++++++++ src/nix/command.hh | 10 ++++++++++ src/nix/dump-path.cc | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 55 insertions(+) create mode 100644 src/nix/dump-path.cc diff --git a/src/nix/command.cc b/src/nix/command.cc index a45f2888b..3c82e0df5 100644 --- a/src/nix/command.cc +++ b/src/nix/command.cc @@ -129,4 +129,14 @@ void StorePathsCommand::run(ref store) run(store, storePaths); } +void StorePathCommand::run(ref store) +{ + auto storePaths = buildInstallables(store, false); + + if (storePaths.size() != 1) + throw UsageError("this command requires exactly one store path"); + + run(store, *storePaths.begin()); +} + } diff --git a/src/nix/command.hh b/src/nix/command.hh index cf0097d78..4800b5c91 100644 --- a/src/nix/command.hh +++ b/src/nix/command.hh @@ -118,6 +118,16 @@ public: bool useDefaultInstallables() override { return !all; } }; +/* A command that operates on exactly one store path. */ +struct StorePathCommand : public InstallablesCommand +{ + using StoreCommand::run; + + virtual void run(ref store, const Path & storePath) = 0; + + void run(ref store) override; +}; + typedef std::map> Commands; /* An argument parser that supports multiple subcommands, diff --git a/src/nix/dump-path.cc b/src/nix/dump-path.cc new file mode 100644 index 000000000..1a1866437 --- /dev/null +++ b/src/nix/dump-path.cc @@ -0,0 +1,35 @@ +#include "command.hh" +#include "store-api.hh" + +using namespace nix; + +struct CmdDumpPath : StorePathCommand +{ + std::string name() override + { + return "dump-path"; + } + + std::string description() override + { + return "dump a store path to stdout (in NAR format)"; + } + + Examples examples() override + { + return { + Example{ + "To get a NAR from the binary cache https://cache.nixos.org/:", + "nix dump-path --store https://cache.nixos.org/ /nix/store/7crrmih8c52r8fbnqb933dxrsp44md93-glibc-2.25" + }, + }; + } + + void run(ref store, const Path & storePath) override + { + FdSink sink(STDOUT_FILENO); + store->narFromPath(storePath, sink); + } +}; + +static RegisterCommand r1(make_ref());