Resolve paths relative to XDG config. paths

This should make the programs an awful lot less painful to set up.

1 files changed, 87 insertions, 45 deletions

diff --git a/src/common.c b/src/common.c
index 2907159..8f7ffd1 100644
--- a/src/common.c
+++ b/src/common.c
@@ -1359,6 +1359,58 @@ get_xdg_home_dir (struct str *output, const char *var, const char *def)
 	}
 }
 
+static void
+get_xdg_config_dirs (struct str_vector *out)
+{
+	struct str config_home;
+	str_init (&config_home);
+	get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config");
+	str_vector_add (out, config_home.str);
+	str_free (&config_home);
+
+	const char *xdg_config_dirs;
+	if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS")))
+		split_str_ignore_empty (xdg_config_dirs, ':', out);
+}
+
+static char *
+resolve_config_filename (const char *filename)
+{
+	// Absolute path is absolute
+	if (*filename == '/')
+		return xstrdup (filename);
+
+	struct str_vector paths;
+	str_vector_init (&paths);
+	get_xdg_config_dirs (&paths);
+
+	struct str file;
+	str_init (&file);
+
+	char *result = NULL;
+	for (unsigned i = 0; i < paths.len; i++)
+	{
+		// As per spec, relative paths are ignored
+		if (*paths.vector[i] != '/')
+			continue;
+
+		str_reset (&file);
+		str_append_printf (&file, "%s/" PROGRAM_NAME "/%s",
+			paths.vector[i], filename);
+
+		struct stat st;
+		if (!stat (file.str, &st))
+		{
+			result = str_steal (&file);
+			break;
+		}
+	}
+
+	str_vector_free (&paths);
+	str_free (&file);
+	return result;
+}
+
 static size_t io_error_domain_tag;
 #define IO_ERROR (error_resolve_domain (&io_error_domain_tag))
 
@@ -1729,45 +1781,6 @@ struct config_item
 	const char *description;
 };
 
-static FILE *
-get_config_file (void)
-{
-	struct str_vector paths;
-	struct str config_home, file;
-	const char *xdg_config_dirs;
-	unsigned i;
-	FILE *fp = NULL;
-
-	str_vector_init (&paths);
-
-	str_init (&config_home);
-	get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config");
-	str_vector_add (&paths, config_home.str);
-	str_free (&config_home);
-
-	if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS")))
-		split_str_ignore_empty (xdg_config_dirs, ':', &paths);
-
-	str_init (&file);
-	for (i = 0; i < paths.len; i++)
-	{
-		// As per spec, relative paths are ignored
-		if (*paths.vector[i] != '/')
-			continue;
-
-		str_reset (&file);
-		str_append (&file, paths.vector[i]);
-		str_append (&file, "/" PROGRAM_NAME "/" PROGRAM_NAME ".conf");
-
-		if ((fp = fopen (file.str, "r")))
-			break;
-	}
-
-	str_free (&file);
-	str_vector_free (&paths);
-	return fp;
-}
-
 static void
 load_config_defaults (struct str_map *config, const struct config_item *table)
 {
@@ -1781,16 +1794,23 @@ load_config_defaults (struct str_map *config, const struct config_item *table)
 static bool
 read_config_file (struct str_map *config, struct error **e)
 {
-	struct str line;
-	FILE *fp = get_config_file ();
-	unsigned line_no = 0;
-	bool errors = false;
+	char *filename = resolve_config_filename (PROGRAM_NAME ".conf");
+	if (!filename)
+		return true;
 
+	FILE *fp = fopen (filename, "r");
 	if (!fp)
-		return true;
+	{
+		error_set (e, IO_ERROR, IO_ERROR_FAILED,
+			"could not open `%s' for reading: %s", filename, strerror (errno));
+		return false;
+	}
 
+	struct str line;
 	str_init (&line);
-	for (line_no = 1; read_line (fp, &line); line_no++)
+
+	bool errors = false;
+	for (unsigned line_no = 1; read_line (fp, &line); line_no++)
 	{
 		char *start = line.str;
 		if (*start == '#')
@@ -1894,3 +1914,25 @@ error:
 	return NULL;
 
 }
+
+static void
+call_write_default_config (const char *hint, const struct config_item *table)
+{
+	static const char *prolog =
+	"# " PROGRAM_NAME " " PROGRAM_VERSION " configuration file\n"
+	"#\n"
+	"# Relative paths are searched for in ${XDG_CONFIG_HOME:-~/.config}\n"
+	"# /" PROGRAM_NAME " as well as in $XDG_CONFIG_DIRS/" PROGRAM_NAME "\n"
+	"\n";
+
+	struct error *e = NULL;
+	char *filename = write_default_config (hint, prolog, table, &e);
+	if (!filename)
+	{
+		print_fatal ("%s", e->message);
+		error_free (e);
+		exit (EXIT_FAILURE);
+	}
+	print_status ("configuration written to `%s'", filename);
+	free (filename);
+}