[glib] gkeyfile: Add some examples to the documentation

[Philip Withnall <pwithnall src gnome org>]

commit a71251dc402044bd80ef9ce9e47bbec7a0572386
Author: Philip Withnall <withnall endlessm com>
Date:   Thu Oct 19 15:48:45 2017 +0100

    gkeyfile: Add some examples to the documentation
    
    Add some examples of loading and saving key files.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=330458

 glib/gkeyfile.c |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 52 insertions(+), 0 deletions(-)
---
diff --git a/glib/gkeyfile.c b/glib/gkeyfile.c
index 8a56c76..6526576 100644
--- a/glib/gkeyfile.c
+++ b/glib/gkeyfile.c
@@ -152,6 +152,58 @@
  * multiple groups with the same name; they are merged together.
  * Another difference is that keys and group names in key files are not
  * restricted to ASCII characters.
+ *
+ * Here is an example of loading a key file and reading a value:
+ * |[<!-- language="C" -->
+ * g_autoptr(GError) error = NULL;
+ * g_autoptr(GKeyFile) key_file = g_key_file_new ();
+ *
+ * if (!g_key_file_load_from_file (key_file, "key-file.ini", flags, &error))
+ *   {
+ *     if (!g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
+ *       g_warning ("Error loading key file: %s", error->message);
+ *     return;
+ *   }
+ *
+ * g_autofree gchar *val = g_key_file_get_string (key_file, "Group Name", "SomeKey", &error);
+ * if (val == NULL &&
+ *     !g_error_matches (error, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_KEY_NOT_FOUND))
+ *   {
+ *     g_warning ("Error finding key in key file: %s", error->message);
+ *     return;
+ *   }
+ * else if (val == NULL)
+ *   {
+ *     // Fall back to a default value.
+ *     val = g_strdup ("default-value");
+ *   }
+ * ]|
+ *
+ * Here is an example of creating and saving a key file:
+ * |[<!-- language="C" -->
+ * g_autoptr(GKeyFile) key_file = g_key_file_new ();
+ * const gchar *val = …;
+ * g_autoptr(GError) error = NULL;
+ *
+ * g_key_file_set_string (key_file, "Group Name", "SomeKey", val);
+ *
+ * // Save as a file.
+ * if (!g_key_file_save_to_file (key_file, "key-file.ini", &error))
+ *   {
+ *     g_warning ("Error saving key file: %s", error->message);
+ *     return;
+ *   }
+ *
+ * // Or store to a GBytes for use elsewhere.
+ * gsize data_len;
+ * g_autofree guint8 *data = (guint8 *) g_key_file_to_data (key_file, &data_len, &error);
+ * if (data == NULL)
+ *   {
+ *     g_warning ("Error saving key file: %s", error->message);
+ *     return;
+ *   }
+ * g_autoptr(GBytes) bytes = g_bytes_new_take (g_steal_pointer (&data), data_len);
+ * ]|
  */
 
 /**