Rename nix show-config to nix config show

Part of #7672

My main motivation is to be able to use `nix.checkConfig`[1]. This
doesn't work with Lix currently since the module uses `nix show-config`
if the Nix version is <2.20pre and `nix config show` otherwise. I think
this is the only instance where nixpkgs checks for which Nix commands
exist that affects us now, so I figured we could just perform the rename
here as well[2] and still provide the current version number[3].

I don't have a strong opinion on whether to deprecate `nix show-config`,
the warning is added there automatically.

(cherry picked from commit f300e11b056dea414d7d77bbc6e5a7dc5d9ddd41)

[1] https://nixos.org/manual/nixos/stable/options.html#opt-nix.checkConfig
[2] I should add that I don't use the "official" ways of installing Lix
    because using the flake directly and callPackaging it seemed to fit
    better into my workflow: I already have a little mess to make
    sure Hydra from the flake uses the correct pkgs.nix and I didn't
    want to complicate it further while keeping a single package-set I
    can build in CI. Don't get me wrong, I think such a module for a
    quick-start is very important, just giving context on why I bother
    in the first place :)
[3] When we go public, I think it's worth considering to add support in
    nixpkgs itself for Lix.

Change-Id: I47b4239b05cbeda3c370d2fa56ea768b768768ac

doc/manual/local.mk

@@ -29,7 +29,7 @@ man-pages += $(foreach subcommand, \
 clean-files += $(d)/*.1 $(d)/*.5 $(d)/*.8
 
 # Provide a dummy environment for nix, so that it will not access files outside the macOS sandbox.
-# Set cores to 0 because otherwise nix show-config resolves the cores based on the current machine
+# Set cores to 0 because otherwise nix config show resolves the cores based on the current machine
 dummy-env = env -i \
 	HOME=/dummy \
 	NIX_CONF_DIR=/dummy \
@@ -89,7 +89,7 @@ doc/manual/generated/in/nix.json: $(doc_nix)
 
 doc/manual/generated/in/conf-file.json: $(doc_nix)
 	@mkdir -p doc/manual/generated/in
-	$(trace-gen) $(dummy-env) $(doc_nix) show-config --json --experimental-features nix-command > $@.tmp
+	$(trace-gen) $(dummy-env) $(doc_nix) config show --json --experimental-features nix-command > $@.tmp
 	@mv $@.tmp $@
 
 doc/manual/generated/in/contributing/experimental-feature-descriptions.md: doc/manual/generated/in/xp-features.json $(d)/utils.nix $(d)/generate-xp-features.nix $(doc_nix)

doc/manual/meson.build

@@ -197,6 +197,8 @@ endforeach
 nix3_manpages = [
   'nix3-build',
   'nix3-bundle',
+  'nix3-config',
+  'nix3-config-show',
   'nix3-copy',
   'nix3-daemon',
   'nix3-derivation-add',
@@ -258,7 +260,6 @@ nix3_manpages = [
   'nix3-run',
   'nix3-search',
   'nix3-shell',
-  'nix3-show-config',
   'nix3-store-add-file',
   'nix3-store-add-path',
   'nix3-store-cat',

doc/manual/rl-next/nix-config-show.md

@@ -0,0 +1,7 @@
+---
+synopsis: rename 'nix show-config' to 'nix config show'
+issues: 7672
+prs: 9477
+---
+
+`nix show-config` was renamed to `nix config show` to be more consistent with the rest of the command-line interface.

doc/manual/src/SUMMARY.md

@@ -91,6 +91,8 @@
     - [nix](command-ref/new-cli/nix.md)
     - [nix build](command-ref/new-cli/nix3-build.md)
     - [nix bundle](command-ref/new-cli/nix3-bundle.md)
+    - [nix config](command-ref/new-cli/nix3-config.md)
+    - [nix config show](command-ref/new-cli/nix3-config-show.md)
     - [nix copy](command-ref/new-cli/nix3-copy.md)
     - [nix daemon](command-ref/new-cli/nix3-daemon.md)
     - [nix derivation](command-ref/new-cli/nix3-derivation.md)

doc/manual/src/command-ref/new-cli/nix3-config-show.md

@@ -0,0 +1 @@
+{{#include @generated@/command-ref/new-cli/nix3-config-show.md}}

doc/manual/src/command-ref/new-cli/nix3-config.md

@@ -0,0 +1 @@
+{{#include @generated@/command-ref/new-cli/nix3-config.md}}

doc/manual/src/command-ref/new-cli/nix3-show-config.md

@@ -1 +0,0 @@
-{{#include @generated@/command-ref/new-cli/nix3-show-config.md}}

src/nix/config.cc

@@ -7,11 +7,31 @@
 
 using namespace nix;
 
-struct CmdShowConfig : Command, MixJSON
+struct CmdConfig : virtual NixMultiCommand
+{
+    CmdConfig() : MultiCommand(RegisterCommand::getCommandsFor({"config"}))
+    { }
+
+    std::string description() override
+    {
+        return "manipulate the Nix configuration";
+    }
+
+    Category category() override { return catUtility; }
+
+    void run() override
+    {
+        if (!command)
+            throw UsageError("'nix config' requires a sub-command.");
+        command->second->run();
+    }
+};
+
+struct CmdConfigShow : Command, MixJSON
 {
     std::optional<std::string> name;
 
-    CmdShowConfig() {
+    CmdConfigShow() {
         expectArgs({
             .label = {"name"},
             .optional = true,
@@ -56,4 +76,5 @@ struct CmdShowConfig : Command, MixJSON
     }
 };
 
-static auto rShowConfig = registerCommand<CmdShowConfig>("show-config");
+static auto rCmdConfig = registerCommand<CmdConfig>("config");
+static auto rShowConfig = registerCommand2<CmdConfigShow>({"config", "show"});

src/nix/main.cc

@@ -151,6 +151,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs, virtual RootArgs
         {"ping-store", {"store", "ping"}},
         {"sign-paths", {"store", "sign"}},
         {"show-derivation", {"derivation", "show"}},
+        {"show-config", {"config", "show"}},
         {"to-base16", {"hash", "to-base16"}},
         {"to-base32", {"hash", "to-base32"}},
         {"to-base64", {"hash", "to-base64"}},

src/nix/meson.build

@@ -59,7 +59,7 @@ nix_sources = files(
   'repl.cc',
   'run.cc',
   'search.cc',
-  'show-config.cc',
+  'config.cc',
   'sigs.cc',
   'store-copy-log.cc',
   'store-delete.cc',

tests/functional/config.sh

@@ -40,19 +40,19 @@ files=$(nix-build --verbose --version | grep "User config" | cut -d ':' -f2- | x
 # Test that it's possible to load the config from a custom location
 here=$(readlink -f "$(dirname "${BASH_SOURCE[0]}")")
 export NIX_USER_CONF_FILES=$here/config/nix-with-substituters.conf
-var=$(nix show-config | grep '^substituters =' | cut -d '=' -f 2 | xargs)
+var=$(nix config show | grep '^substituters =' | cut -d '=' -f 2 | xargs)
 [[ $var == https://example.com ]]
 
 # Test that it's possible to load config from the environment
-prev=$(nix show-config | grep '^cores' | cut -d '=' -f 2 | xargs)
+prev=$(nix config show | grep '^cores' | cut -d '=' -f 2 | xargs)
 export NIX_CONFIG="cores = 4242"$'\n'"experimental-features = nix-command flakes"
-exp_cores=$(nix show-config | grep '^cores' | cut -d '=' -f 2 | xargs)
+exp_cores=$(nix config show | grep '^cores' | cut -d '=' -f 2 | xargs)
-exp_features=$(nix show-config | grep '^experimental-features' | cut -d '=' -f 2 | xargs)
+exp_features=$(nix config show | grep '^experimental-features' | cut -d '=' -f 2 | xargs)
 [[ $prev != $exp_cores ]]
 [[ $exp_cores == "4242" ]]
 [[ $exp_features == "flakes nix-command" ]]
 
 # Test that it's possible to retrieve a single setting's value
-val=$(nix show-config | grep '^warn-dirty' | cut -d '=' -f  2 | xargs)
+val=$(nix config show | grep '^warn-dirty' | cut -d '=' -f  2 | xargs)
-val2=$(nix show-config warn-dirty)
+val2=$(nix config show warn-dirty)
 [[ $val == $val2 ]]

tests/functional/experimental-features.sh

@@ -31,7 +31,7 @@ source common.sh
 NIX_CONFIG='
   experimental-features = nix-command
   accept-flake-config = true
-' nix show-config accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
+' nix config show accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
 grepQuiet "false" $TEST_ROOT/stdout
 grepQuiet "Ignoring setting 'accept-flake-config' because experimental feature 'flakes' is not enabled" $TEST_ROOT/stderr
 
@@ -39,7 +39,7 @@ grepQuiet "Ignoring setting 'accept-flake-config' because experimental feature '
 NIX_CONFIG='
   accept-flake-config = true
   experimental-features = nix-command
-' nix show-config accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
+' nix config show accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
 grepQuiet "false" $TEST_ROOT/stdout
 grepQuiet "Ignoring setting 'accept-flake-config' because experimental feature 'flakes' is not enabled" $TEST_ROOT/stderr
 
@@ -47,7 +47,7 @@ grepQuiet "Ignoring setting 'accept-flake-config' because experimental feature '
 NIX_CONFIG='
   experimental-features = nix-command flakes
   accept-flake-config = true
-' nix show-config accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
+' nix config show accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
 grepQuiet "true" $TEST_ROOT/stdout
 grepQuietInverse "Ignoring setting 'accept-flake-config'" $TEST_ROOT/stderr
 
@@ -55,7 +55,7 @@ grepQuietInverse "Ignoring setting 'accept-flake-config'" $TEST_ROOT/stderr
 NIX_CONFIG='
   accept-flake-config = true
   experimental-features = nix-command flakes
-' nix show-config accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
+' nix config show accept-flake-config 1>$TEST_ROOT/stdout 2>$TEST_ROOT/stderr
 grepQuiet "true" $TEST_ROOT/stdout
 grepQuietInverse "Ignoring setting 'accept-flake-config'" $TEST_ROOT/stderr