nix-super/src/nix/config.cc
Théophane Hufschmitt 7fff625e39
Improve the error message for “multicommands” commands (#9510)
* Factor out the default `MultiCommand` behavior

All the `MultiCommand`s had (nearly) the same behavior when called
without a subcommand.
Factor out this behavior into the `NixMultiCommand` class.

* Display the list of available subcommands when none is specified

Whenever a user runs a command that excepts a subcommand, add the list
of available subcommands to the error message.

* Print the multi-command lists as Markdown lists

This takes more screen real estate, but is also much more readable than
a comma-separated list
2023-12-06 13:13:45 +00:00

73 lines
1.8 KiB
C++

#include "command.hh"
#include "common-args.hh"
#include "shared.hh"
#include "store-api.hh"
#include <nlohmann/json.hpp>
using namespace nix;
struct CmdConfig : NixMultiCommand
{
CmdConfig() : NixMultiCommand("config", RegisterCommand::getCommandsFor({"config"}))
{ }
std::string description() override
{
return "manipulate the Nix configuration";
}
Category category() override { return catUtility; }
};
struct CmdConfigShow : Command, MixJSON
{
std::optional<std::string> name;
CmdConfigShow() {
expectArgs({
.label = {"name"},
.optional = true,
.handler = {&name},
});
}
std::string description() override
{
return "show the Nix configuration or the value of a specific setting";
}
Category category() override { return catUtility; }
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) {
// FIXME: use appropriate JSON types (bool, ints, etc).
logger->cout("%s", globalConfig.toJSON().dump());
} else {
logger->cout("%s", globalConfig.toKeyValue());
}
}
};
static auto rCmdConfig = registerCommand<CmdConfig>("config");
static auto rShowConfig = registerCommand2<CmdConfigShow>({"config", "show"});