text: /*************************************************************************/
  /*  os_unix.cpp                                                          */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #include "os_unix.h"
  
  #ifdef UNIX_ENABLED
  
  #include "core/os/thread_dummy.h"
  #include "core/project_settings.h"
  #include "drivers/unix/dir_access_unix.h"
  #include "drivers/unix/file_access_unix.h"
  #include "drivers/unix/net_socket_posix.h"
  #include "drivers/unix/rw_lock_posix.h"
  #include "drivers/unix/thread_posix.h"
  #include "servers/visual_server.h"
  
  #ifdef __APPLE__
  #include <mach-o/dyld.h>
  #include <mach/mach_time.h>
  #endif
  
  #if defined(__FreeBSD__) || defined(__OpenBSD__)
  #include <sys/param.h>
  #include <sys/sysctl.h>
  #endif
  
  #include <assert.h>
  #include <dlfcn.h>
  #include <errno.h>
  #include <poll.h>
  #include <signal.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/time.h>
  #include <sys/wait.h>
  #include <unistd.h>
  
  /// Clock Setup function (used by get_ticks_usec)
  static uint64_t _clock_start = 0;
  #if defined(__APPLE__)
  static double _clock_scale = 0;
  static void _setup_clock() {
  	mach_timebase_info_data_t info;
  	kern_return_t ret = mach_timebase_info(&info);
  	ERR_FAIL_COND_MSG(ret != 0, "OS CLOCK IS NOT WORKING!");
  	_clock_scale = ((double)info.numer / (double)info.denom) / 1000.0;
  	_clock_start = mach_absolute_time() * _clock_scale;
  }
  #else
  #if defined(CLOCK_MONOTONIC_RAW) && !defined(JAVASCRIPT_ENABLED) // This is a better clock on Linux.
  #define GODOT_CLOCK CLOCK_MONOTONIC_RAW
  #else
  #define GODOT_CLOCK CLOCK_MONOTONIC
  #endif
  static void _setup_clock() {
  	struct timespec tv_now = { 0, 0 };
  	ERR_FAIL_COND_MSG(clock_gettime(GODOT_CLOCK, &tv_now) != 0, "OS CLOCK IS NOT WORKING!");
  	_clock_start = ((uint64_t)tv_now.tv_nsec / 1000L) + (uint64_t)tv_now.tv_sec * 1000000L;
  }
  #endif
  
  void OS_Unix::debug_break() {
  
  	assert(false);
  };
  
  static void handle_interrupt(int sig) {
  	if (ScriptDebugger::get_singleton() == NULL)
  		return;
  
  	ScriptDebugger::get_singleton()->set_depth(-1);
  	ScriptDebugger::get_singleton()->set_lines_left(1);
  }
  
  void OS_Unix::initialize_debugging() {
  
  	if (ScriptDebugger::get_singleton() != NULL) {
  		struct sigaction action;
  		memset(&action, 0, sizeof(action));
  		action.sa_handler = handle_interrupt;
  		sigaction(SIGINT, &action, NULL);
  	}
  }
  
  int OS_Unix::unix_initialize_audio(int p_audio_driver) {
  
  	return 0;
  }
  
  void OS_Unix::initialize_core() {
  
  #ifdef NO_THREADS
  	ThreadDummy::make_default();
  	RWLockDummy::make_default();
  #else
  	ThreadPosix::make_default();
  	RWLockPosix::make_default();
  #endif
  	FileAccess::make_default<FileAccessUnix>(FileAccess::ACCESS_RESOURCES);
  	FileAccess::make_default<FileAccessUnix>(FileAccess::ACCESS_USERDATA);
  	FileAccess::make_default<FileAccessUnix>(FileAccess::ACCESS_FILESYSTEM);
  	//FileAccessBufferedFA<FileAccessUnix>::make_default();
  	DirAccess::make_default<DirAccessUnix>(DirAccess::ACCESS_RESOURCES);
  	DirAccess::make_default<DirAccessUnix>(DirAccess::ACCESS_USERDATA);
  	DirAccess::make_default<DirAccessUnix>(DirAccess::ACCESS_FILESYSTEM);
  
  #ifndef NO_NETWORK
  	NetSocketPosix::make_default();
  	IP_Unix::make_default();
  #endif
  
  	_setup_clock();
  }
  
  void OS_Unix::finalize_core() {
  
  	NetSocketPosix::cleanup();
  }
  
  void OS_Unix::alert(const String &p_alert, const String &p_title) {
  
  	fprintf(stderr, "ERROR: %s\n", p_alert.utf8().get_data());
  }
  
  String OS_Unix::get_stdin_string(bool p_block) {
  
  	if (p_block) {
  		char buff[1024];
  		String ret = stdin_buf + fgets(buff, 1024, stdin);
  		stdin_buf = "";
  		return ret;
  	}
  
  	return "";
  }
  
  String OS_Unix::get_name() const {
  
  	return "Unix";
  }
  
  uint64_t OS_Unix::get_unix_time() const {
  
  	return time(NULL);
  };
  
  uint64_t OS_Unix::get_system_time_secs() const {
  	struct timeval tv_now;
  	gettimeofday(&tv_now, NULL);
  	return uint64_t(tv_now.tv_sec);
  }
  
  uint64_t OS_Unix::get_system_time_msecs() const {
  	struct timeval tv_now;
  	gettimeofday(&tv_now, NULL);
  	return uint64_t(tv_now.tv_sec) * 1000 + uint64_t(tv_now.tv_usec) / 1000;
  }
  
  OS::Date OS_Unix::get_date(bool utc) const {
  
  	time_t t = time(NULL);
  	struct tm *lt;
  	if (utc)
  		lt = gmtime(&t);
  	else
  		lt = localtime(&t);
  	Date ret;
  	ret.year = 1900 + lt->tm_year;
  	// Index starting at 1 to match OS_Unix::get_date
  	//   and Windows SYSTEMTIME and tm_mon follows the typical structure
  	//   of 0-11, noted here: http://www.cplusplus.com/reference/ctime/tm/
  	ret.month = (Month)(lt->tm_mon + 1);
  	ret.day = lt->tm_mday;
  	ret.weekday = (Weekday)lt->tm_wday;
  	ret.dst = lt->tm_isdst;
  
  	return ret;
  }
  
  OS::Time OS_Unix::get_time(bool utc) const {
  	time_t t = time(NULL);
  	struct tm *lt;
  	if (utc)
  		lt = gmtime(&t);
  	else
  		lt = localtime(&t);
  	Time ret;
  	ret.hour = lt->tm_hour;
  	ret.min = lt->tm_min;
  	ret.sec = lt->tm_sec;
  	get_time_zone_info();
  	return ret;
  }
  
  OS::TimeZoneInfo OS_Unix::get_time_zone_info() const {
  	time_t t = time(NULL);
  	struct tm *lt = localtime(&t);
  	char name[16];
  	strftime(name, 16, "%Z", lt);
  	name[15] = 0;
  	TimeZoneInfo ret;
  	ret.name = name;
  
  	char bias_buf[16];
  	strftime(bias_buf, 16, "%z", lt);
  	int bias;
  	bias_buf[15] = 0;
  	sscanf(bias_buf, "%d", &bias);
  
  	// convert from ISO 8601 (1 minute=1, 1 hour=100) to minutes
  	int hour = (int)bias / 100;
  	int minutes = bias % 100;
  	if (bias < 0)
  		ret.bias = hour * 60 - minutes;
  	else
  		ret.bias = hour * 60 + minutes;
  
  	return ret;
  }
  
  void OS_Unix::delay_usec(uint32_t p_usec) const {
  
  	struct timespec rem = { static_cast<time_t>(p_usec / 1000000), (static_cast<long>(p_usec) % 1000000) * 1000 };
  	while (nanosleep(&rem, &rem) == EINTR) {
  	}
  }
  uint64_t OS_Unix::get_ticks_usec() const {
  
  #if defined(__APPLE__)
  	uint64_t longtime = mach_absolute_time() * _clock_scale;
  #else
  	// Unchecked return. Static analyzers might complain.
  	// If _setup_clock() succeeded, we assume clock_gettime() works.
  	struct timespec tv_now = { 0, 0 };
  	clock_gettime(GODOT_CLOCK, &tv_now);
  	uint64_t longtime = ((uint64_t)tv_now.tv_nsec / 1000L) + (uint64_t)tv_now.tv_sec * 1000000L;
  #endif
  	longtime -= _clock_start;
  
  	return longtime;
  }
  
  Error OS_Unix::execute(const String &p_path, const List<String> &p_arguments, bool p_blocking, ProcessID *r_child_id, String *r_pipe, int *r_exitcode, bool read_stderr, Mutex *p_pipe_mutex) {
  
  #ifdef __EMSCRIPTEN__
  	// Don't compile this code at all to avoid undefined references.
  	// Actual virtual call goes to OS_JavaScript.
  	ERR_FAIL_V(ERR_BUG);
  #else
  	if (p_blocking && r_pipe) {
  
  		String argss;
  		argss = "\"" + p_path + "\"";
  
  		for (int i = 0; i < p_arguments.size(); i++) {
  
  			argss += String(" \"") + p_arguments[i] + "\"";
  		}
  
  		if (read_stderr) {
  			argss += " 2>&1"; // Read stderr too
  		} else {
  			argss += " 2>/dev/null"; //silence stderr
  		}
  		FILE *f = popen(argss.utf8().get_data(), "r");
  
  		ERR_FAIL_COND_V_MSG(!f, ERR_CANT_OPEN, "Cannot pipe stream from process running with following arguments '" + argss + "'.");
  
  		char buf[65535];
  
  		while (fgets(buf, 65535, f)) {
  
  			if (p_pipe_mutex) {
  				p_pipe_mutex->lock();
  			}
  			(*r_pipe) += String::utf8(buf);
  			if (p_pipe_mutex) {
  				p_pipe_mutex->unlock();
  			}
  		}
  		int rv = pclose(f);
  		if (r_exitcode)
  			*r_exitcode = WEXITSTATUS(rv);
  
  		return OK;
  	}
  
  	pid_t pid = fork();
  	ERR_FAIL_COND_V(pid < 0, ERR_CANT_FORK);
  
  	if (pid == 0) {
  		// is child
  
  		if (!p_blocking) {
  			// For non blocking calls, create a new session-ID so parent won't wait for it.
  			// This ensures the process won't go zombie at end.
  			setsid();
  		}
  
  		Vector<CharString> cs;
  		cs.push_back(p_path.utf8());
  		for (int i = 0; i < p_arguments.size(); i++)
  			cs.push_back(p_arguments[i].utf8());
  
  		Vector<char *> args;
  		for (int i = 0; i < cs.size(); i++)
  			args.push_back((char *)cs[i].get_data());
  		args.push_back(0);
  
  		execvp(p_path.utf8().get_data(), &args[0]);
  		// still alive? something failed..
  		fprintf(stderr, "**ERROR** OS_Unix::execute - Could not create child process while executing: %s\n", p_path.utf8().get_data());
  		abort();
  	}
  
  	if (p_blocking) {
  
  		int status;
  		waitpid(pid, &status, 0);
  		if (r_exitcode)
  			*r_exitcode = WEXITSTATUS(status);
  
  	} else {
  
  		if (r_child_id)
  			*r_child_id = pid;
  	}
  
  	return OK;
  #endif
  }
  
  Error OS_Unix::kill(const ProcessID &p_pid) {
  
  	int ret = ::kill(p_pid, SIGKILL);
  	if (!ret) {
  		//avoid zombie process
  		int st;
  		::waitpid(p_pid, &st, 0);
  	}
  	return ret ? ERR_INVALID_PARAMETER : OK;
  }
  
  int OS_Unix::get_process_id() const {
  
  	return getpid();
  };
  
  bool OS_Unix::has_environment(const String &p_var) const {
  
  	return getenv(p_var.utf8().get_data()) != NULL;
  }
  
  String OS_Unix::get_locale() const {
  
  	if (!has_environment("LANG"))
  		return "en";
  
  	String locale = get_environment("LANG");
  	int tp = locale.find(".");
  	if (tp != -1)
  		locale = locale.substr(0, tp);
  	return locale;
  }
  
  Error OS_Unix::open_dynamic_library(const String p_path, void *&p_library_handle, bool p_also_set_library_path) {
  
  	String path = p_path;
  
  	if (FileAccess::exists(path) && path.is_rel_path()) {
  		// dlopen expects a slash, in this case a leading ./ for it to be interpreted as a relative path,
  		//  otherwise it will end up searching various system directories for the lib instead and finally failing.
  		path = "./" + path;
  	}
  
  	if (!FileAccess::exists(path)) {
  		//this code exists so gdnative can load .so files from within the executable path
  		path = get_executable_path().get_base_dir().plus_file(p_path.get_file());
  	}
  
  	if (!FileAccess::exists(path)) {
  		//this code exists so gdnative can load .so files from a standard unix location
  		path = get_executable_path().get_base_dir().plus_file("../lib").plus_file(p_path.get_file());
  	}
  
  	p_library_handle = dlopen(path.utf8().get_data(), RTLD_NOW);
  	ERR_FAIL_COND_V_MSG(!p_library_handle, ERR_CANT_OPEN, "Can't open dynamic library: " + p_path + ". Error: " + dlerror());
  	return OK;
  }
  
  Error OS_Unix::close_dynamic_library(void *p_library_handle) {
  	if (dlclose(p_library_handle)) {
  		return FAILED;
  	}
  	return OK;
  }
  
  Error OS_Unix::get_dynamic_library_symbol_handle(void *p_library_handle, const String p_name, void *&p_symbol_handle, bool p_optional) {
  	const char *error;
  	dlerror(); // Clear existing errors
  
  	p_symbol_handle = dlsym(p_library_handle, p_name.utf8().get_data());
  
  	error = dlerror();
  	if (error != NULL) {
  		ERR_FAIL_COND_V_MSG(!p_optional, ERR_CANT_RESOLVE, "Can't resolve symbol " + p_name + ". Error: " + error + ".");
  
  		return ERR_CANT_RESOLVE;
  	}
  	return OK;
  }
  
  Error OS_Unix::set_cwd(const String &p_cwd) {
  
  	if (chdir(p_cwd.utf8().get_data()) != 0)
  		return ERR_CANT_OPEN;
  
  	return OK;
  }
  
  String OS_Unix::get_environment(const String &p_var) const {
  
  	if (getenv(p_var.utf8().get_data()))
  		return getenv(p_var.utf8().get_data());
  	return "";
  }
  
  bool OS_Unix::set_environment(const String &p_var, const String &p_value) const {
  
  	return setenv(p_var.utf8().get_data(), p_value.utf8().get_data(), /* overwrite: */ true) == 0;
  }
  
  int OS_Unix::get_processor_count() const {
  
  	return sysconf(_SC_NPROCESSORS_CONF);
  }
  
  String OS_Unix::get_user_data_dir() const {
  
  	String appname = get_safe_dir_name(ProjectSettings::get_singleton()->get("application/config/name"));
  	if (appname != "") {
  		bool use_custom_dir = ProjectSettings::get_singleton()->get("application/config/use_custom_user_dir");
  		if (use_custom_dir) {
  			String custom_dir = get_safe_dir_name(ProjectSettings::get_singleton()->get("application/config/custom_user_dir_name"), true);
  			if (custom_dir == "") {
  				custom_dir = appname;
  			}
  			return get_data_path().plus_file(custom_dir);
  		} else {
  			return get_data_path().plus_file(get_godot_dir_name()).plus_file("app_userdata").plus_file(appname);
  		}
  	}
  
  	return ProjectSettings::get_singleton()->get_resource_path();
  }
  
  String OS_Unix::get_executable_path() const {
  
  #ifdef __linux__
  	//fix for running from a symlink
  	char buf[256];
  	memset(buf, 0, 256);
  	ssize_t len = readlink("/proc/self/exe", buf, sizeof(buf));
  	String b;
  	if (len > 0) {
  		b.parse_utf8(buf, len);
  	}
  	if (b == "") {
  		WARN_PRINT("Couldn't get executable path from /proc/self/exe, using argv[0]");
  		return OS::get_executable_path();
  	}
  	return b;
  #elif defined(__OpenBSD__)
  	char resolved_path[MAXPATHLEN];
  
  	realpath(OS::get_executable_path().utf8().get_data(), resolved_path);
  
  	return String(resolved_path);
  #elif defined(__FreeBSD__)
  	int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
  	char buf[MAXPATHLEN];
  	size_t len = sizeof(buf);
  	if (sysctl(mib, 4, buf, &len, NULL, 0) != 0) {
  		WARN_PRINT("Couldn't get executable path from sysctl");
  		return OS::get_executable_path();
  	}
  	String b;
  	b.parse_utf8(buf);
  	return b;
  #elif defined(__APPLE__)
  	char temp_path[1];
  	uint32_t buff_size = 1;
  	_NSGetExecutablePath(temp_path, &buff_size);
  
  	char *resolved_path = new char[buff_size + 1];
  
  	if (_NSGetExecutablePath(resolved_path, &buff_size) == 1)
  		WARN_PRINT("MAXPATHLEN is too small");
  
  	String path(resolved_path);
  	delete[] resolved_path;
  
  	return path;
  #else
  	ERR_PRINT("Warning, don't know how to obtain executable path on this OS! Please override this function properly.");
  	return OS::get_executable_path();
  #endif
  }
  
  void UnixTerminalLogger::log_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type) {
  	if (!should_log(true)) {
  		return;
  	}
  
  	const char *err_details;
  	if (p_rationale && p_rationale[0])
  		err_details = p_rationale;
  	else
  		err_details = p_code;
  
  	// Disable color codes if stdout is not a TTY.
  	// This prevents Godot from writing ANSI escape codes when redirecting
  	// stdout and stderr to a file.
  	const bool tty = isatty(fileno(stdout));
  	const char *gray = tty ? "\E[0;90m" : "";
  	const char *red = tty ? "\E[0;91m" : "";
  	const char *red_bold = tty ? "\E[1;31m" : "";
  	const char *yellow = tty ? "\E[0;93m" : "";
  	const char *yellow_bold = tty ? "\E[1;33m" : "";
  	const char *magenta = tty ? "\E[0;95m" : "";
  	const char *magenta_bold = tty ? "\E[1;35m" : "";
  	const char *cyan = tty ? "\E[0;96m" : "";
  	const char *cyan_bold = tty ? "\E[1;36m" : "";
  	const char *reset = tty ? "\E[0m" : "";
  
  	switch (p_type) {
  		case ERR_WARNING:
  			logf_error("%sWARNING:%s %s\n", yellow_bold, yellow, err_details);
  			logf_error("%s     at: %s (%s:%i)%s\n", gray, p_function, p_file, p_line, reset);
  			break;
  		case ERR_SCRIPT:
  			logf_error("%sSCRIPT ERROR:%s %s\n", magenta_bold, magenta, err_details);
  			logf_error("%s          at: %s (%s:%i)%s\n", gray, p_function, p_file, p_line, reset);
  			break;
  		case ERR_SHADER:
  			logf_error("%sSHADER ERROR:%s %s\n", cyan_bold, cyan, err_details);
  			logf_error("%s          at: %s (%s:%i)%s\n", gray, p_function, p_file, p_line, reset);
  			break;
  		case ERR_ERROR:
  		default:
  			logf_error("%sERROR:%s %s\n", red_bold, red, err_details);
  			logf_error("%s   at: %s (%s:%i)%s\n", gray, p_function, p_file, p_line, reset);
  			break;
  	}
  }
  
  UnixTerminalLogger::~UnixTerminalLogger() {}
  
  OS_Unix::OS_Unix() {
  	Vector<Logger *> loggers;
  	loggers.push_back(memnew(UnixTerminalLogger));
  	_set_logger(memnew(CompositeLogger(loggers)));
  }
  
  #endif
  