nix/show-config: allow getting the value of a specific setting

Instead of needing to run `nix show-config --json | jq -r
'."warn-dirty".value'` to view the value of `warn-dirty`, you can now
run `nix show-config warn-dirty`.
This commit is contained in:
Cole Helbling 2023-01-12 13:42:17 -08:00
parent eaa20f2574
commit 1fc74afbba

View file

@ -9,15 +9,44 @@ using namespace nix;
struct CmdShowConfig : Command, MixJSON struct CmdShowConfig : Command, MixJSON
{ {
std::optional<std::string> name;
CmdShowConfig() {
expectArgs({
.label = {"name"},
.optional = true,
.handler = {&name},
});
}
std::string description() override std::string description() override
{ {
return "show the Nix configuration"; return "show the Nix configuration or the value of a specific setting";
} }
Category category() override { return catUtility; } Category category() override { return catUtility; }
void run() override void run() override
{ {
if (name) {
if (json) {
throw UsageError("'--json' is not supported when specifying a setting name");
}
std::map<std::string, Config::SettingInfo> settings;
globalConfig.getSettings(settings);
auto setting = settings.find(*name);
if (setting == settings.end()) {
throw Error("could not find setting '%1%'", *name);
} else {
const auto & value = setting->second.value;
logger->cout("%s", value);
}
return;
}
if (json) { if (json) {
// FIXME: use appropriate JSON types (bool, ints, etc). // FIXME: use appropriate JSON types (bool, ints, etc).
logger->cout("%s", globalConfig.toJSON().dump()); logger->cout("%s", globalConfig.toJSON().dump());