Merge #4471

4471: Add open_file, works on macOS, safer, Add buttons to open settings file and config directory r=heinrich5991 a=def-

<img width="1790" alt="Screenshot 2021-12-19 at 01 23 12" src="https://user-images.githubusercontent.com/2335377/146659150-2945d3d4-d6e9-41b2-834d-54487a9b91cd.png">
## Checklist

- [x] Tested the change ingame
- [x] Provided screenshots if it is a visual change
- [x] Tested in combination with possibly related configuration options
- [ ] Written a unit test if it works standalone, system.c especially
- [x] Considered possible null pointers and out of bounds array indexing
- [x] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: def <dennis@felsin9.de>

src/base/system.cpp

@@ -3666,13 +3666,26 @@ int open_link(const char *link)
 	MultiByteToWideChar(CP_UTF8, 0, link, -1, wBuffer, sizeof(wBuffer) / sizeof(WCHAR));
 	return (uintptr_t)ShellExecuteW(NULL, L"open", wBuffer, NULL, NULL, SW_SHOWDEFAULT) > 32;
 #elif defined(CONF_PLATFORM_LINUX)
-	char aBuf[512];
+	const int pid = fork();
-	str_format(aBuf, sizeof(aBuf), "xdg-open %s >/dev/null 2>&1 &", link);
+	if(pid == 0)
-	return system(aBuf) == 0;
+		execlp("xdg-open", "xdg-open", link, nullptr);
+	return pid > 0;
 #elif defined(CONF_FAMILY_UNIX)
-	char aBuf[512];
+	const int pid = fork();
-	str_format(aBuf, sizeof(aBuf), "open %s &", link);
+	if(pid == 0)
-	return system(aBuf) == 0;
+		execlp("open", "open", link, nullptr);
+	return pid > 0;
+#endif
+}
+
+int open_file(const char *path)
+{
+#if defined(CONF_PLATFORM_MACOS)
+	return open_link(path);
+#else
+	char buf[512];
+	str_format(buf, sizeof(buf), "file://%s", path);
+	return open_link(buf);
 #endif
 }
 

src/base/system.h

@@ -1815,10 +1815,25 @@ int net_socket_read_wait(NETSOCKET sock, int time);
 		Returns 1 on success, 0 on failure.
 
 	Remarks:
-		This may not be called with untrusted input or it'll result in arbitrary code execution.
+		This may not be called with untrusted input or it'll result in arbitrary code execution, especially on Windows.
 */
 int open_link(const char *link);
 
+/*
+	Function: open_file
+		Opens a file or directory with default program.
+
+	Parameters:
+		path - The path to open.
+
+	Returns:
+		Returns 1 on success, 0 on failure.
+
+	Remarks:
+		This may not be called with untrusted input or it'll result in arbitrary code execution, especially on Windows.
+*/
+int open_file(const char *path);
+
 void swap_endian(void *data, unsigned elem_size, unsigned num);
 
 typedef void (*DBG_LOGGER)(const char *line, void *user);

src/game/client/components/menus_demo.cpp

@@ -1254,13 +1254,11 @@ void CMenus::RenderDemoList(CUIRect MainView)
 	if(DoButton_Menu(&s_DirectoryButtonID, Localize("Demos directory"), 0, &DirectoryButton))
 	{
 		char aBuf[IO_MAX_PATH_LENGTH];
-		char aBufFull[IO_MAX_PATH_LENGTH + 7];
 		Storage()->GetCompletePath(IStorage::TYPE_SAVE, "demos", aBuf, sizeof(aBuf));
 		Storage()->CreateFolder("demos", IStorage::TYPE_SAVE);
-		str_format(aBufFull, sizeof(aBufFull), "file://%s", aBuf);
+		if(!open_file(aBuf))
-		if(!open_link(aBufFull))
 		{
-			dbg_msg("menus", "couldn't open link");
+			dbg_msg("menus", "couldn't open file");
 		}
 	}
 

src/game/client/components/menus_settings.cpp

@@ -258,6 +258,38 @@ void CMenus::RenderSettingsGeneral(CUIRect MainView)
 			m_NeedRestartGeneral = s_ClShowConsole != g_Config.m_ClShowConsole;
 #endif
 
+		Left.HSplitTop(15.0f, 0, &Left);
+		CUIRect SettingsButton;
+		Left.HSplitBottom(25.0f, &Left, &SettingsButton);
+
+		SettingsButton.HSplitTop(5.0f, 0, &SettingsButton);
+		static int s_SettingsButtonID = 0;
+		if(DoButton_Menu(&s_SettingsButtonID, Localize("Settings file"), 0, &SettingsButton))
+		{
+			char aBuf[IO_MAX_PATH_LENGTH];
+			Storage()->GetCompletePath(IStorage::TYPE_SAVE, "settings_ddnet.cfg", aBuf, sizeof(aBuf));
+			if(!open_file(aBuf))
+			{
+				dbg_msg("menus", "couldn't open file");
+			}
+		}
+
+		Left.HSplitTop(15.0f, 0, &Left);
+		CUIRect ConfigButton;
+		Left.HSplitBottom(25.0f, &Left, &ConfigButton);
+
+		ConfigButton.HSplitTop(5.0f, 0, &ConfigButton);
+		static int s_ConfigButtonID = 0;
+		if(DoButton_Menu(&s_ConfigButtonID, Localize("Config directory"), 0, &ConfigButton))
+		{
+			char aBuf[IO_MAX_PATH_LENGTH];
+			Storage()->GetCompletePath(IStorage::TYPE_SAVE, "", aBuf, sizeof(aBuf));
+			if(!open_file(aBuf))
+			{
+				dbg_msg("menus", "couldn't open file");
+			}
+		}
+
 		Left.HSplitTop(15.0f, 0, &Left);
 		CUIRect DirectoryButton;
 		Left.HSplitBottom(25.0f, &Left, &DirectoryButton);
@@ -268,13 +300,11 @@ void CMenus::RenderSettingsGeneral(CUIRect MainView)
 		if(DoButton_Menu(&s_ThemesButtonID, Localize("Themes directory"), 0, &DirectoryButton))
 		{
 			char aBuf[IO_MAX_PATH_LENGTH];
-			char aBufFull[IO_MAX_PATH_LENGTH + 7];
 			Storage()->GetCompletePath(IStorage::TYPE_SAVE, "themes", aBuf, sizeof(aBuf));
 			Storage()->CreateFolder("themes", IStorage::TYPE_SAVE);
-			str_format(aBufFull, sizeof(aBufFull), "file://%s", aBuf);
+			if(!open_file(aBuf))
-			if(!open_link(aBufFull))
 			{
-				dbg_msg("menus", "couldn't open link");
+				dbg_msg("menus", "couldn't open file");
 			}
 		}
 
@@ -733,13 +763,11 @@ void CMenus::RenderSettingsTee(CUIRect MainView)
 	if(DoButton_Menu(&s_DirectoryButtonID, Localize("Skins directory"), 0, &DirectoryButton))
 	{
 		char aBuf[IO_MAX_PATH_LENGTH];
-		char aBufFull[IO_MAX_PATH_LENGTH + 7];
 		Storage()->GetCompletePath(IStorage::TYPE_SAVE, "skins", aBuf, sizeof(aBuf));
 		Storage()->CreateFolder("skins", IStorage::TYPE_SAVE);
-		str_format(aBufFull, sizeof(aBufFull), "file://%s", aBuf);
+		if(!open_file(aBuf))
-		if(!open_link(aBufFull))
 		{
-			dbg_msg("menus", "couldn't open link");
+			dbg_msg("menus", "couldn't open file");
 		}
 	}
 

src/game/client/components/menus_settings_assets.cpp

@@ -547,10 +547,9 @@ void CMenus::RenderSettingsCustom(CUIRect MainView)
 		Storage()->GetCompletePath(IStorage::TYPE_SAVE, aBufFull, aBuf, sizeof(aBuf));
 		Storage()->CreateFolder("assets", IStorage::TYPE_SAVE);
 		Storage()->CreateFolder(aBufFull, IStorage::TYPE_SAVE);
-		str_format(aBufFull, sizeof(aBufFull), "file://%s", aBuf);
+		if(!open_file(aBuf))
-		if(!open_link(aBufFull))
 		{
-			dbg_msg("menus", "couldn't open link");
+			dbg_msg("menus", "couldn't open file");
 		}
 	}