Configuration and TOML
++ +
MontaukOS provides a small header-only C++ API for reading and writing
+TOML configuration files from userspace. Include
+<montauk/config.h> for file-backed configuration and
+<montauk/toml.h> for the in-memory TOML document model.
Configuration locations
+ +System configuration is stored in 0:/config. The API accepts a
+name without the .toml extension:
0:/config/desktop.toml
+0:/config/network.tomlPer-user configuration is stored below the user directory:
+ +0:/users/<username>/config/<name>.tomlLoading and saving
+ +#include <montauk/config.h>
+
+auto doc = montauk::config::load("desktop");
+const char* theme = doc.get_string("appearance.theme", "light");
+
+montauk::config::set_string(&doc, "appearance.theme", "dark");
+int result = montauk::config::save("desktop", &doc);
+
+doc.destroy();load() returns an initialized empty document if the file does
+not exist. save() creates the configuration directory and returns
+0 on success or a negative value on error. Saving rewrites the
+whole file.
System configuration API
+ +toml::Doc config::load(const char* name);
+int config::save(const char* name, toml::Doc* doc);
+int config::remove(const char* name);Per-user configuration API
+ +toml::Doc config::load_user(const char* username, const char* name);
+int config::save_user(const char* username,
+ const char* name,
+ toml::Doc* doc);For example:
+ +auto doc = montauk::config::load_user("alice", "desktop");
+bool clock24 = doc.get_bool("display.clock_24h", false);
+
+montauk::config::set_bool(&doc, "display.clock_24h", true);
+montauk::config::save_user("alice", "desktop", &doc);
+doc.destroy();Reading values
+ +Keys may use dotted paths corresponding to TOML tables:
+ +[server]
+host = "pool.ntp.org"
+port = 123
+enabled = trueconst char* host = doc.get_string("server.host", "localhost");
+int64_t port = doc.get_int("server.port", 80);
+bool enabled = doc.get_bool("server.enabled", false);Typed getters return their default when the key is absent or has another +type. The available value types are:
+ +toml::Type::String
+toml::Type::Int
+toml::Type::Bool
+toml::Type::Array
+toml::Type::TableArrays and tables are returned as toml::Value*. Their children
+are available through value->array.items and
+value->array.count:
auto* names = doc.get_array("server.names");
+if (names) {
+ for (int i = 0; i < names->array.count; ++i) {
+ auto* item = names->array.items[i];
+ if (item->type == montauk::toml::Type::String)
+ montauk::print(item->str);
+ }
+}Modifying documents
+ +void config::set_string(toml::Doc* doc,
+ const char* key, const char* value);
+void config::set_int(toml::Doc* doc,
+ const char* key, int64_t value);
+void config::set_bool(toml::Doc* doc,
+ const char* key, bool value);
+bool config::unset(toml::Doc* doc, const char* key);The setters overwrite an existing value or append a new one. The
+unset() return value is true when a matching key was
+removed.
Parsing and serialization
+ +Use toml::parse() when TOML is already available in memory:
const char* text =
+ "[server]\n"
+ "port = 8080\n"
+ "enabled = true\n";
+
+auto doc = montauk::toml::parse(text);
+int64_t port = doc.get_int("server.port");
+doc.destroy();A document can be serialized to newly allocated TOML text:
+ +char* text = montauk::config::serialize(&doc);
+// Use text...
+montauk::mfree(text);Serialization produces normalized TOML and does not preserve comments or +the original formatting.
+ +Memory ownership
+ +toml::Doc owns its parsed values and strings. Every document
+returned by load(), load_user(), or
+toml::parse() must eventually be released with
+doc.destroy().
When constructing a document manually, initialize it before using the +mutation helpers:
+ +montauk::toml::Doc doc;
+doc.init();
+montauk::config::set_bool(&doc, "enabled", true);
+montauk::config::save("example", &doc);
+doc.destroy();Supported TOML features
+ +The userspace parser supports strings, literal and multiline strings, +integers (including hexadecimal, octal, and binary forms), booleans, arrays, +tables, inline tables, dotted keys, and comments.
+ +There are no typed float or datetime accessors. Callers should also treat +configuration names and usernames as safe path components, since they are +used to construct filesystem paths.
+ ++ + + +