move file output to a separate display-file

src/CMakeLists.txt

@@ -110,6 +110,8 @@ set(conky_sources
     display-output.hh
     display-console.cc
     display-console.hh
+    display-file.cc
+    display-file.hh
     display-ncurses.cc
     display-ncurses.hh
     display-http.cc

src/conky.cc

@@ -310,15 +310,6 @@ conky::range_config_setting<int> net_avg_samples("net_avg_samples", 1, 14, 2,
 conky::range_config_setting<int> diskio_avg_samples("diskio_avg_samples", 1, 14,
                                                     2, true);
 
-/* filenames for output */
-static conky::simple_config_setting<std::string> overwrite_file(
-    "overwrite_file", std::string(), true);
-static FILE *overwrite_fpointer = nullptr;
-static conky::simple_config_setting<std::string> append_file("append_file",
-                                                             std::string(),
-                                                             true);
-static FILE *append_fpointer = nullptr;
-
 #ifdef BUILD_X11
 
 static conky::simple_config_setting<bool> show_graph_scale("show_graph_scale",
@@ -1073,12 +1064,6 @@ static void draw_string(const char *s) {
 #ifdef BUILD_X11
   width_of_s = get_string_width(s);
 #endif /* BUILD_X11 */
-  if (draw_mode == FG && (overwrite_fpointer != nullptr)) {
-    fprintf(overwrite_fpointer, "%s\n", s);
-  }
-  if (draw_mode == FG && (append_fpointer != nullptr)) {
-    fprintf(append_fpointer, "%s\n", s);
-  }
   if (conky::active_display_outputs.size() && draw_mode == FG)
     for (auto output : conky::active_display_outputs)
       output->draw_string(s, width_of_s);
@@ -1672,18 +1657,7 @@ static void draw_stuff() {
   cimlib_render(text_start_x, text_start_y, window.width, window.height);
 #endif /* BUILD_IMLIB2 */
 #endif /* BUILD_X11 */
-  if (static_cast<unsigned int>(!overwrite_file.get(*state).empty()) != 0u) {
-    overwrite_fpointer = fopen(overwrite_file.get(*state).c_str(), "we");
-    if (overwrite_fpointer == nullptr) {
-      NORM_ERR("Cannot overwrite '%s'", overwrite_file.get(*state).c_str());
-    }
-  }
-  if (static_cast<unsigned int>(!append_file.get(*state).empty()) != 0u) {
-    append_fpointer = fopen(append_file.get(*state).c_str(), "ae");
-    if (append_fpointer == nullptr) {
-      NORM_ERR("Cannot append to '%s'", append_file.get(*state).c_str());
-    }
-  }
+  for (auto output : display_outputs()) output->begin_draw_stuff();
 #ifdef BUILD_X11
   llua_draw_pre_hook();
   if (out_to_x.get(*state)) {
@@ -1723,14 +1697,7 @@ static void draw_stuff() {
   if (out_to_x.get(*state)) { xpmdb_swap_buffers(); }
 #endif
 #endif /* BUILD_X11 && BUILD_XDBE */
-  if (overwrite_fpointer != nullptr) {
-    fclose(overwrite_fpointer);
-    overwrite_fpointer = nullptr;
-  }
-  if (append_fpointer != nullptr) {
-    fclose(append_fpointer);
-    append_fpointer = nullptr;
-  }
+  for (auto output : display_outputs()) output->end_draw_stuff();
 }
 
 #ifdef BUILD_X11

src/display-file.cc

@@ -0,0 +1,106 @@
+/*
+ *
+ * Conky, a system monitor, based on torsmo
+ *
+ * Please see COPYING for details
+ *
+ * Copyright (C) 2018 François Revol et al.
+ * Copyright (c) 2004, Hannu Saransaari and Lauri Hakkarainen
+ * Copyright (c) 2005-2019 Brenden Matthews, Philip Kovacs, et. al.
+ *	(see AUTHORS)
+ * All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <config.h>
+
+#include "conky.h"
+#include "display-file.hh"
+#include "nc.h"
+
+#include <iostream>
+#include <sstream>
+#include <unordered_map>
+
+/* filenames for output */
+static conky::simple_config_setting<std::string> overwrite_file(
+    "overwrite_file", std::string(), true);
+static FILE *overwrite_fpointer = nullptr;
+static conky::simple_config_setting<std::string> append_file("append_file",
+                                                             std::string(),
+                                                             true);
+static FILE *append_fpointer = nullptr;
+
+namespace conky {
+namespace {
+
+conky::display_output_file file_output("file");
+
+}  // namespace
+
+namespace priv {}  // namespace priv
+
+display_output_file::display_output_file(const std::string &name_)
+    : display_output_base(name_) {
+  // lowest priority, it's a fallback
+  priority = 0;
+}
+
+bool display_output_file::detect() {
+  if (static_cast<unsigned int>(!overwrite_file.get(*state).empty()) != 0u ||
+      static_cast<unsigned int>(!append_file.get(*state).empty()) != 0u) {
+    std::cerr << "Display output '" << name << "' enabled in config."
+              << std::endl;
+    return true;
+  }
+  return false;
+}
+
+bool display_output_file::initialize() { return true; }
+
+bool display_output_file::shutdown() { return true; }
+
+void display_output_file::draw_string(const char *s, int w) {
+  if (overwrite_fpointer != nullptr) { fprintf(overwrite_fpointer, "%s\n", s); }
+  if (append_fpointer != nullptr) { fprintf(append_fpointer, "%s\n", s); }
+}
+
+void display_output_file::begin_draw_stuff() {
+  if (static_cast<unsigned int>(!overwrite_file.get(*state).empty()) != 0u) {
+    overwrite_fpointer = fopen(overwrite_file.get(*state).c_str(), "we");
+    if (overwrite_fpointer == nullptr) {
+      NORM_ERR("Cannot overwrite '%s'", overwrite_file.get(*state).c_str());
+    }
+  }
+  if (static_cast<unsigned int>(!append_file.get(*state).empty()) != 0u) {
+    append_fpointer = fopen(append_file.get(*state).c_str(), "ae");
+    if (append_fpointer == nullptr) {
+      NORM_ERR("Cannot append to '%s'", append_file.get(*state).c_str());
+    }
+  }
+}
+
+void display_output_file::end_draw_stuff() {
+  if (overwrite_fpointer != nullptr) {
+    fclose(overwrite_fpointer);
+    overwrite_fpointer = nullptr;
+  }
+  if (append_fpointer != nullptr) {
+    fclose(append_fpointer);
+    append_fpointer = nullptr;
+  }
+}
+
+}  // namespace conky

src/display-file.hh

@@ -0,0 +1,60 @@
+/*
+ *
+ * Conky, a system monitor, based on torsmo
+ *
+ * Please see COPYING for details
+ *
+ * Copyright (C) 2018 François Revol et al.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef DISPLAY_FILE_HH
+#define DISPLAY_FILE_HH
+
+#include <limits>
+#include <string>
+#include <type_traits>
+
+#include "display-output.hh"
+#include "luamm.hh"
+
+namespace conky {
+
+/*
+ * A base class for file display output.
+ */
+class display_output_file : public display_output_base {
+ public:
+  explicit display_output_file(const std::string &name_);
+
+  virtual ~display_output_file() {}
+
+  // check if available and enabled in settings
+  virtual bool detect();
+  // connect to DISPLAY and other stuff
+  virtual bool initialize();
+  virtual bool shutdown();
+
+  virtual void draw_string(const char *s, int w);
+
+  virtual void begin_draw_stuff();
+  virtual void end_draw_stuff();
+
+  // file-specific
+};
+
+}  // namespace conky
+
+#endif /* DISPLAY_FILE_HH */