Merge pull request #7595 from cole-h/show-setting-value

nix/show-config: allow getting the value of a specific setting
This commit is contained in:
Eelco Dolstra 2023-01-23 17:56:39 +01:00 committed by GitHub
commit f503ba1b8b
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2 changed files with 35 additions and 1 deletions

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@ -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());

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@ -51,3 +51,8 @@ exp_features=$(nix show-config | grep '^experimental-features' | cut -d '=' -f 2
[[ $prev != $exp_cores ]] [[ $prev != $exp_cores ]]
[[ $exp_cores == "4242" ]] [[ $exp_cores == "4242" ]]
[[ $exp_features == "flakes nix-command" ]] [[ $exp_features == "flakes nix-command" ]]
# Test that it's possible to retrieve a single setting's value
val=$(nix show-config | grep '^warn-dirty' | cut -d '=' -f 2 | xargs)
val2=$(nix show-config warn-dirty)
[[ $val == $val2 ]]