settings: add setting_desc_check() helper

Rudimentary setting value checking against the description.

For now it just enforces the multiple-choice stuff, I'm undecided
on the regex support for now.  It'd just be nice to throw some
more informative errors when cli arguments are incorrect for things
like fullscreen=yes when it only knows fullscreen=on/off.

2 files changed, 21 insertions, 0 deletions

diff --git a/src/settings.c b/src/settings.c
index c24c280..c7419e1 100644
--- a/src/settings.c
+++ b/src/settings.c
@@ -289,6 +289,26 @@ void setting_desc_free(setting_desc_t *desc)
 }
 
 
+int setting_desc_check(const setting_desc_t *desc, const char *value)
+{
+	assert(desc);
+
+	if (desc->values) {
+
+		for (int i = 0; desc->values[i]; i++) {
+			if (!strcasecmp(desc->values[i], value))
+				return 0;
+		}
+
+		return -EINVAL;
+	}
+
+	/* TODO: apply regex check */
+
+	return 0;
+}
+
+
 /* wrapper around sprintf for convenient buffer size computation */
 /* supply NULL buf when computing size, size and offset are ignored.
  * supply non-NULL for actual writing into buf of size bytes @ offset.
diff --git a/src/settings.h b/src/settings.h
index 26baca7..198f8b6 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -32,6 +32,7 @@ int settings_apply_desc_generators(const settings_t *settings, const setting_des
 
 int setting_desc_clone(const setting_desc_t *desc, setting_desc_t **res_desc);
 void setting_desc_free(setting_desc_t *desc);
+int setting_desc_check(const setting_desc_t *desc, const char *value);
 
 #ifndef SETTINGS_STR
 #define _SETTINGS_STR(s)	#s