Add $DBUS variable for exec

Fixes #375

doc/man/zathura.1.rst

@@ -230,7 +230,8 @@ close
 
 exec
   Execute an external command. ``$FILE`` expands to the current document path,
-  and ``$PAGE`` to the current page number
+  ``$PAGE`` to the current page number, and ``$DBUS`` to the bus name of the
+  D-Bus interface
 
 info
   Show document information

doc/man/zathurarc.5.rst

@@ -232,7 +232,8 @@ They can also be combined with modifiers:
   * ``exec``:
 
     Execute an external command. ``$FILE`` expands to the current document path,
-    and ``$PAGE`` to the current page number.
+    ``$PAGE`` to the current page number, and ``$DBUS`` to the bus name of the
+    D-Bus interface.
 
   * ``focus_inputbar``
 

zathura/commands.c

@@ -9,6 +9,7 @@
 #include "commands.h"
 #include "config.h"
 #include "database.h"
+#include "dbus-interface.h"
 #include "document.h"
 #include "internal.h"
 #include "page-widget.h"
@@ -544,6 +545,12 @@ cmd_exec(girara_session_t* session, girara_list_t* argument_list)
     return false;
   }
 
+  const char* bus_name = zathura_dbus_get_name(zathura);
+  GIRARA_LIST_FOREACH_BODY_WITH_ITER(
+    argument_list, char*, iter, value, char* s = girara_replace_substring(value, "$DBUS", bus_name); if (s != NULL) {
+      girara_list_iterator_set(iter, s);
+    });
+
   if (zathura->document != NULL) {
     const char*  path = zathura_document_get_path(zathura->document);
     unsigned int page = zathura_document_get_current_page_number(zathura->document);

zathura/dbus-interface.c

@@ -40,6 +40,7 @@ typedef struct private_s {
   GDBusConnection* connection;
   guint            owner_id;
   guint            registration_id;
+  char*            bus_name;
 } ZathuraDbusPrivate;
 
 G_DEFINE_TYPE_WITH_CODE(ZathuraDbus, zathura_dbus, G_TYPE_OBJECT, G_ADD_PRIVATE(ZathuraDbus))
@@ -71,6 +72,8 @@ finalize(GObject* object)
     g_dbus_node_info_unref(priv->introspection_data);
   }
 
+  g_free(priv->bus_name);
+
   G_OBJECT_CLASS(zathura_dbus_parent_class)->finalize(object);
 }
 
@@ -91,6 +94,7 @@ zathura_dbus_init(ZathuraDbus* dbus)
   priv->connection         = NULL;
   priv->owner_id           = 0;
   priv->registration_id    = 0;
+  priv->bus_name           = NULL;
 }
 
 static void
@@ -168,13 +172,21 @@ zathura_dbus_new(zathura_t* zathura)
   }
 
   char* well_known_name = g_strdup_printf(DBUS_NAME_TEMPLATE, getpid());
+  priv->bus_name        = well_known_name;
   priv->owner_id        = g_bus_own_name(G_BUS_TYPE_SESSION, well_known_name, G_BUS_NAME_OWNER_FLAGS_NONE, bus_acquired,
                                          name_acquired, name_lost, dbus, NULL);
-  g_free(well_known_name);
 
   return dbus;
 }
 
+const char*
+zathura_dbus_get_name(zathura_t* zathura)
+{
+  ZathuraDbusPrivate* priv = zathura_dbus_get_instance_private(zathura->dbus);
+
+  return priv->bus_name;
+}
+
 void
 zathura_dbus_edit(ZathuraDbus* edit, unsigned int page, unsigned int x, unsigned int y)
 {

zathura/dbus-interface.h

@@ -40,6 +40,7 @@ struct zathura_dbus_class_s
 GType zathura_dbus_get_type(void) G_GNUC_CONST;
 
 ZathuraDbus* zathura_dbus_new(zathura_t* zathura);
+const char* zathura_dbus_get_name(zathura_t* zathura);
 
 /**
  * Emit the 'Edit' signal on the D-Bus connection.

zathura/shortcuts.c

@@ -10,6 +10,7 @@
 
 #include "callbacks.h"
 #include "shortcuts.h"
+#include "dbus-interface.h"
 #include "document.h"
 #include "zathura.h"
 #include "render.h"
@@ -1492,33 +1493,40 @@ sc_exec(girara_session_t* session, girara_argument_t* argument, girara_event_t*
     return false;
   }
 
+  girara_argument_t new_argument = *argument;
+  const char* bus_name           = zathura_dbus_get_name(zathura);
+  char* s                        = girara_replace_substring(new_argument.data, "$DBUS", bus_name);
+  if (s == NULL) {
+    return false;
+  }
+  new_argument.data = s;
+
   if (zathura->document != NULL) {
     const char* path = zathura_document_get_path(zathura->document);
     unsigned int page = zathura_document_get_current_page_number(zathura->document);
     char page_buf[G_ASCII_DTOSTR_BUF_SIZE];
     g_ascii_dtostr(page_buf, G_ASCII_DTOSTR_BUF_SIZE, page+1);
 
-    girara_argument_t new_argument = *argument;
-
-    char* r = girara_replace_substring(argument->data, "$FILE", path);
-    if (r == NULL) {
-      return false;
-    }
-
-    char* s = girara_replace_substring(r, "$PAGE", page_buf);
-    g_free(r);
+    s = girara_replace_substring(new_argument.data, "$FILE", path);
+    g_free(new_argument.data);
+
+    if (s == NULL) {
+      return false;
+    }
+    new_argument.data = s;
+
+    s = girara_replace_substring(new_argument.data, "$PAGE", page_buf);
+    g_free(new_argument.data);
 
     if (s == NULL) {
       return false;
     }
-
     new_argument.data = s;
-    const bool ret = girara_sc_exec(session, &new_argument, event, t);
-    g_free(s);
-    return ret;
   }
 
-  return girara_sc_exec(session, argument, event, t);
+  const bool ret = girara_sc_exec(session, &new_argument, event, t);
+  g_free(new_argument.data);
+  return ret;
 }
 
 bool