X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=device.c;h=141e3cfd2c9edb35887c02a0a2ff3acb891c4f2c;hb=9a6e8ec4bc84d94e27c9a004a7b75caaa0ba7124;hp=19192ecbb0b69b404529df45d374be955d1962c9;hpb=b20ea789170c7bb52c54b23c0167992bceb9a330;p=sigrok-cli.git

diff --git a/device.c b/device.c
index 19192ec..141e3cf 100644
--- a/device.c
+++ b/device.c
@@ -63,7 +63,20 @@ GSList *device_scan(void)
 	return devices;
 }
 
-struct sr_channel_group *select_channel_group(struct sr_dev_inst *sdi)
+/**
+ * Lookup a channel group from its name.
+ *
+ * Uses the previously stored option value to lookup a channel group.
+ * Returns a reference to the channel group when the lookup succeeded,
+ * or #NULL after lookup failure, or #NULL for the global channel group
+ * (the device's global parameters). Emits an error message when the
+ * lookup failed while a channel group's name was specified.
+ *
+ * @param[in] sdi Device instance.
+ *
+ * @returns The channel group, or #NULL for failed lookup.
+ */
+struct sr_channel_group *lookup_channel_group(struct sr_dev_inst *sdi)
 {
 	struct sr_channel_group *cg;
 	GSList *l, *channel_groups;
@@ -72,7 +85,6 @@ struct sr_channel_group *select_channel_group(struct sr_dev_inst *sdi)
 		return NULL;
 
 	channel_groups = sr_dev_inst_channel_groups_get(sdi);
-
 	if (!channel_groups) {
 		g_critical("This device does not have any channel groups.");
 		return NULL;
@@ -80,9 +92,9 @@ struct sr_channel_group *select_channel_group(struct sr_dev_inst *sdi)
 
 	for (l = channel_groups; l; l = l->next) {
 		cg = l->data;
-		if (!g_ascii_strcasecmp(opt_channel_group, cg->name)) {
-			return cg;
-		}
+		if (g_ascii_strcasecmp(opt_channel_group, cg->name) != 0)
+			continue;
+		return cg;
 	}
 	g_critical("Invalid channel group '%s'", opt_channel_group);