tools: add a blurb to each tool to list what it is for

Let's not force users/developers to dig through the commit log to figure
out what each tool does.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

tools/ei-demo-client.c

@@ -21,6 +21,19 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+/* A simple tool that provides a libei client that sends a fixed set of
+ * events every second.
+ *
+ * This tool is useful for testing EIS implementations, to make sure we can
+ * a connection, we receive devices and that we can send events.
+ *
+ * Usually, you'd want to:
+ * - run the eis-demo-server (or some other EIS implementation)
+ * - run the eis-fake-portal (if testing portal clients), otherwise
+ *   export LIBEI_SOCKET=eis-0, or whatever value was given.
+ * - run the ei-demo-client
+ */
+
 #include "config.h"
 
 #include <assert.h>

tools/eis-demo-server.c

@@ -21,6 +21,22 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+/* A simple tool that provides an EIS implementation that prints incoming
+ * events.
+ *
+ * This tool is useful for testing libei event flow, to make sure the
+ * connection works and events arrive at the EIS implementation.
+ *
+ * The server has hardcoded regions and creates fixed devices, it's really
+ * just for basic purposes.
+ *
+ * Usually, you'd want to:
+ * - run the eis-demo-server (or some other EIS implementation)
+ * - run the eis-fake-portal (if testing portal clients), otherwise
+ *   export LIBEI_SOCKET=eis-0, or whatever value was given.
+ * - run the libei client
+ */
+
 #include "config.h"
 
 #include <assert.h>

tools/eis-fake-impl-portal.c

@@ -21,6 +21,22 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+/* A simple tool that sets up the org.freedesktop.impl.portal.EmulatedInput
+ * DBus interface and provides the required functionality.
+ *
+ * This tool is useful for testing portals (e.g.
+ * xdg-desktop-portal) that need to connect to impl.portal. It provides
+ * enough data to succeed with the connection.
+ *
+ * This tool does not run an EIS server, use e.g. the eis-demo-server.
+ *
+ * Usually, you'd want to:
+ * - run the eis-demo-server (or some other EIS implementation)
+ * - run the eis-fake-impl-portal
+ * - run xdg-desktop-portal
+ * - run the libei client relying on the portal
+ */
+
 #include "config.h"
 
 #include <errno.h>

tools/eis-fake-portal.c

@@ -21,6 +21,20 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+/* A simple tool that sets up the org.freedesktop.portal.EmulatedInput DBus
+ * interface and provides the required functionality.
+ *
+ * This tool is useful for testing the libei portal backend, it provides just
+ * enough data to have that backend succeed with the connection.
+ *
+ * This tool does not run an EIS server, use e.g. the eis-demo-server.
+ *
+ * Usually, you'd want to:
+ * - run the eis-demo-server (or some other EIS implementation)
+ * - run the eis-fake-portal
+ * - run the libei client relying on the portal
+ */
+
 #include "config.h"
 
 #include <errno.h>