Add include command

sway/commands.c

@@ -95,6 +95,7 @@ static struct cmd_handler handlers[] = {
 	{ "exec", cmd_exec },
 	{ "exec_always", cmd_exec_always },
 	{ "exit", cmd_exit },
+	{ "include", cmd_include },
 };
 
 static int handler_compare(const void *_a, const void *_b) {

sway/commands/include.c

@@ -0,0 +1,15 @@
+#include "sway/commands.h"
+#include "sway/config.h"
+
+struct cmd_results *cmd_include(int argc, char **argv) {
+	struct cmd_results *error = NULL;
+	if ((error = checkarg(argc, "include", EXPECTED_EQUAL_TO, 1))) {
+		return error;
+	}
+
+	if (!load_include_configs(argv[0], config)) {
+		return cmd_results_new(CMD_INVALID, "include", "Failed to include sub configuration file: %s", argv[0]);
+	}
+
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}

sway/config.c

@@ -311,6 +311,95 @@ bool load_main_config(const char *file, bool is_active) {
 	return success;
 }
 
+static bool load_include_config(const char *path, const char *parent_dir, struct sway_config *config) {
+	// save parent config
+	const char *parent_config = config->current_config;
+
+	char *full_path = strdup(path);
+	int len = strlen(path);
+	if (len >= 1 && path[0] != '/') {
+		len = len + strlen(parent_dir) + 2;
+		full_path = malloc(len * sizeof(char));
+		if (!full_path) {
+			sway_log(L_ERROR, "Unable to allocate full path to included config");
+			return false;
+		}
+		snprintf(full_path, len, "%s/%s", parent_dir, path);
+	}
+
+	char *real_path = realpath(full_path, NULL);
+	free(full_path);
+
+	if (real_path == NULL) {
+		sway_log(L_DEBUG, "%s not found.", path);
+		return false;
+	}
+
+	// check if config has already been included
+	int j;
+	for (j = 0; j < config->config_chain->length; ++j) {
+		char *old_path = config->config_chain->items[j];
+		if (strcmp(real_path, old_path) == 0) {
+			sway_log(L_DEBUG, "%s already included once, won't be included again.", real_path);
+			free(real_path);
+			return false;
+		}
+	}
+
+	config->current_config = real_path;
+	list_add(config->config_chain, real_path);
+	int index = config->config_chain->length - 1;
+
+	if (!load_config(real_path, config)) {
+		free(real_path);
+		config->current_config = parent_config;
+		list_del(config->config_chain, index);
+		return false;
+	}
+
+	// restore current_config
+	config->current_config = parent_config;
+	return true;
+}
+
+bool load_include_configs(const char *path, struct sway_config *config) {
+	char *wd = getcwd(NULL, 0);
+	char *parent_path = strdup(config->current_config);
+	const char *parent_dir = dirname(parent_path);
+
+	if (chdir(parent_dir) < 0) {
+		free(parent_path);
+		free(wd);
+		return false;
+	}
+
+	wordexp_t p;
+
+	if (wordexp(path, &p, 0) < 0) {
+		free(parent_path);
+		free(wd);
+		return false;
+	}
+
+	char **w = p.we_wordv;
+	size_t i;
+	for (i = 0; i < p.we_wordc; ++i) {
+		load_include_config(w[i], parent_dir, config);
+	}
+	free(parent_path);
+	wordfree(&p);
+
+	// restore wd
+	if (chdir(wd) < 0) {
+		free(wd);
+		sway_log(L_ERROR, "failed to restore working directory");
+		return false;
+	}
+
+	free(wd);
+	return true;
+}
+
 bool read_config(FILE *file, struct sway_config *config) {
 	bool success = true;
 	enum cmd_status block = CMD_BLOCK_END;

sway/meson.build

@@ -5,6 +5,7 @@ sway_sources = files(
 	'commands/exit.c',
 	'commands/exec.c',
 	'commands/exec_always.c',
+	'commands/include.c',
 	'config.c',
 	'ipc-json.c',
 	'ipc-server.c',