text: /*
   * vim:ts=4:sw=4:expandtab
   *
   * i3 - an improved dynamic tiling window manager
   * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
   *
   * util.c: Utility functions, which can be useful everywhere within i3 (see
   *         also libi3).
   *
   */
  #include "all.h"
  
  #include <sys/wait.h>
  #include <stdarg.h>
  #if defined(__OpenBSD__)
  #include <sys/cdefs.h>
  #endif
  #include <fcntl.h>
  #include <pwd.h>
  #include <yajl/yajl_version.h>
  #include <libgen.h>
  #include <ctype.h>
  
  #define SN_API_NOT_YET_FROZEN 1
  #include <libsn/sn-launcher.h>
  
  int min(int a, int b) {
      return (a < b ? a : b);
  }
  
  int max(int a, int b) {
      return (a > b ? a : b);
  }
  
  bool rect_contains(Rect rect, uint32_t x, uint32_t y) {
      return (x >= rect.x &&
              x <= (rect.x + rect.width) &&
              y >= rect.y &&
              y <= (rect.y + rect.height));
  }
  
  Rect rect_add(Rect a, Rect b) {
      return (Rect){a.x + b.x,
                    a.y + b.y,
                    a.width + b.width,
                    a.height + b.height};
  }
  
  Rect rect_sub(Rect a, Rect b) {
      return (Rect){a.x - b.x,
                    a.y - b.y,
                    a.width - b.width,
                    a.height - b.height};
  }
  
  Rect rect_sanitize_dimensions(Rect rect) {
      rect.width = (int32_t)rect.width <= 0 ? 1 : rect.width;
      rect.height = (int32_t)rect.height <= 0 ? 1 : rect.height;
      return rect;
  }
  
  bool rect_equals(Rect a, Rect b) {
      return a.x == b.x && a.y == b.y && a.width == b.width && a.height == b.height;
  }
  
  /*
   * Returns true if the name consists of only digits.
   *
   */
  __attribute__((pure)) bool name_is_digits(const char *name) {
      /* positive integers and zero are interpreted as numbers */
      for (size_t i = 0; i < strlen(name); i++)
          if (!isdigit(name[i]))
              return false;
  
      return true;
  }
  
  /*
   * Set 'out' to the layout_t value for the given layout. The function
   * returns true on success or false if the passed string is not a valid
   * layout name.
   *
   */
  bool layout_from_name(const char *layout_str, layout_t *out) {
      if (strcmp(layout_str, "default") == 0) {
          *out = L_DEFAULT;
          return true;
      } else if (strcasecmp(layout_str, "stacked") == 0 ||
                 strcasecmp(layout_str, "stacking") == 0) {
          *out = L_STACKED;
          return true;
      } else if (strcasecmp(layout_str, "tabbed") == 0) {
          *out = L_TABBED;
          return true;
      } else if (strcasecmp(layout_str, "splitv") == 0) {
          *out = L_SPLITV;
          return true;
      } else if (strcasecmp(layout_str, "splith") == 0) {
          *out = L_SPLITH;
          return true;
      }
  
      return false;
  }
  
  /*
   * Parses the workspace name as a number. Returns -1 if the workspace should be
   * interpreted as a "named workspace".
   *
   */
  int ws_name_to_number(const char *name) {
      /* positive integers and zero are interpreted as numbers */
      char *endptr = NULL;
      errno = 0;
      long long parsed_num = strtoll(name, &endptr, 10);
      if (errno != 0 || parsed_num > INT32_MAX || parsed_num < 0 || endptr == name) {
          parsed_num = -1;
      }
  
      return parsed_num;
  }
  
  /*
   * Updates *destination with new_value and returns true if it was changed or false
   * if it was the same
   *
   */
  bool update_if_necessary(uint32_t *destination, const uint32_t new_value) {
      uint32_t old_value = *destination;
  
      return ((*destination = new_value) != old_value);
  }
  
  /*
   * exec()s an i3 utility, for example the config file migration script or
   * i3-nagbar. This function first searches $PATH for the given utility named,
   * then falls back to the dirname() of the i3 executable path and then falls
   * back to the dirname() of the target of /proc/self/exe (on linux).
   *
   * This function should be called after fork()ing.
   *
   * The first argument of the given argv vector will be overwritten with the
   * executable name, so pass NULL.
   *
   * If the utility cannot be found in any of these locations, it exits with
   * return code 2.
   *
   */
  void exec_i3_utility(char *name, char *argv[]) {
      /* start the migration script, search PATH first */
      char *migratepath = name;
      argv[0] = migratepath;
      execvp(migratepath, argv);
  
      /* if the script is not in path, maybe the user installed to a strange
       * location and runs the i3 binary with an absolute path. We use
       * argv[0]’s dirname */
      char *pathbuf = sstrdup(start_argv[0]);
      char *dir = dirname(pathbuf);
      sasprintf(&migratepath, "%s/%s", dir, name);
      argv[0] = migratepath;
      execvp(migratepath, argv);
  
  #if defined(__linux__)
      /* on linux, we have one more fall-back: dirname(/proc/self/exe) */
      char buffer[BUFSIZ];
      if (readlink("/proc/self/exe", buffer, BUFSIZ) == -1) {
          warn("could not read /proc/self/exe");
          _exit(EXIT_FAILURE);
      }
      dir = dirname(buffer);
      sasprintf(&migratepath, "%s/%s", dir, name);
      argv[0] = migratepath;
      execvp(migratepath, argv);
  #endif
  
      warn("Could not start %s", name);
      _exit(2);
  }
  
  /*
   * Checks if the given path exists by calling stat().
   *
   */
  bool path_exists(const char *path) {
      struct stat buf;
      return (stat(path, &buf) == 0);
  }
  
  /*
   * Goes through the list of arguments (for exec()) and add/replace the given option,
   * including the option name, its argument, and the option character.
   */
  static char **add_argument(char **original, char *opt_char, char *opt_arg, char *opt_name) {
      int num_args;
      for (num_args = 0; original[num_args] != NULL; num_args++)
          ;
      char **result = scalloc(num_args + 3, sizeof(char *));
  
      /* copy the arguments, but skip the ones we'll replace */
      int write_index = 0;
      bool skip_next = false;
      for (int i = 0; i < num_args; ++i) {
          if (skip_next) {
              skip_next = false;
              continue;
          }
          if (!strcmp(original[i], opt_char) ||
              (opt_name && !strcmp(original[i], opt_name))) {
              if (opt_arg)
                  skip_next = true;
              continue;
          }
          result[write_index++] = original[i];
      }
  
      /* add the arguments we'll replace */
      result[write_index++] = opt_char;
      result[write_index] = opt_arg;
  
      return result;
  }
  
  #define y(x, ...) yajl_gen_##x(gen, ##__VA_ARGS__)
  #define ystr(str) yajl_gen_string(gen, (unsigned char *)str, strlen(str))
  
  static char *store_restart_layout(void) {
      setlocale(LC_NUMERIC, "C");
      yajl_gen gen = yajl_gen_alloc(NULL);
  
      dump_node(gen, croot, true);
  
      setlocale(LC_NUMERIC, "");
  
      const unsigned char *payload;
      size_t length;
      y(get_buf, &payload, &length);
  
      /* create a temporary file if one hasn't been specified, or just
       * resolve the tildes in the specified path */
      char *filename;
      if (config.restart_state_path == NULL) {
          filename = get_process_filename("restart-state");
          if (!filename)
              return NULL;
      } else {
          filename = resolve_tilde(config.restart_state_path);
      }
  
      /* create the directory, it could have been cleaned up before restarting or
       * may not exist at all in case it was user-specified. */
      char *filenamecopy = sstrdup(filename);
      char *base = dirname(filenamecopy);
      DLOG("Creating \"%s\" for storing the restart layout\n", base);
      if (mkdirp(base, DEFAULT_DIR_MODE) != 0)
          ELOG("Could not create \"%s\" for storing the restart layout, layout will be lost.\n", base);
      free(filenamecopy);
  
      int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
      if (fd == -1) {
          perror("open()");
          free(filename);
          return NULL;
      }
  
      if (writeall(fd, payload, length) == -1) {
          ELOG("Could not write restart layout to \"%s\", layout will be lost: %s\n", filename, strerror(errno));
          free(filename);
          close(fd);
          return NULL;
      }
  
      close(fd);
  
      if (length > 0) {
          DLOG("layout: %.*s\n", (int)length, payload);
      }
  
      y(free);
  
      return filename;
  }
  
  /*
   * Restart i3 in-place
   * appends -a to argument list to disable autostart
   *
   */
  void i3_restart(bool forget_layout) {
      char *restart_filename = forget_layout ? NULL : store_restart_layout();
  
      kill_nagbar(&config_error_nagbar_pid, true);
      kill_nagbar(&command_error_nagbar_pid, true);
  
      restore_geometry();
  
      ipc_shutdown(SHUTDOWN_REASON_RESTART, -1);
  
      LOG("restarting \"%s\"...\n", start_argv[0]);
      /* make sure -a is in the argument list or add it */
      start_argv = add_argument(start_argv, "-a", NULL, NULL);
  
      /* make debuglog-on persist */
      if (get_debug_logging()) {
          start_argv = add_argument(start_argv, "-d", "all", NULL);
      }
  
      /* replace -r <file> so that the layout is restored */
      if (restart_filename != NULL) {
          start_argv = add_argument(start_argv, "--restart", restart_filename, "-r");
      }
  
      execvp(start_argv[0], start_argv);
  
      /* not reached */
  }
  
  /*
   * Escapes the given string if a pango font is currently used.
   * If the string has to be escaped, the input string will be free'd.
   *
   */
  char *pango_escape_markup(char *input) {
      if (!font_is_pango())
          return input;
  
      char *escaped = g_markup_escape_text(input, -1);
      FREE(input);
  
      return escaped;
  }
  
  /*
   * Handler which will be called when we get a SIGCHLD for the nagbar, meaning
   * it exited (or could not be started, depending on the exit code).
   *
   */
  static void nagbar_exited(EV_P_ ev_child *watcher, int revents) {
      ev_child_stop(EV_A_ watcher);
  
      if (!WIFEXITED(watcher->rstatus)) {
          ELOG("ERROR: i3-nagbar did not exit normally.\n");
          return;
      }
  
      int exitcode = WEXITSTATUS(watcher->rstatus);
      DLOG("i3-nagbar process exited with status %d\n", exitcode);
      if (exitcode == 2) {
          ELOG("ERROR: i3-nagbar could not be found. Is it correctly installed on your system?\n");
      }
  
      *((pid_t *)watcher->data) = -1;
  }
  
  /*
   * Cleanup handler. Will be called when i3 exits. Kills i3-nagbar with signal
   * SIGKILL (9) to make sure there are no left-over i3-nagbar processes.
   *
   */
  static void nagbar_cleanup(EV_P_ ev_cleanup *watcher, int revent) {
      pid_t *nagbar_pid = (pid_t *)watcher->data;
      if (*nagbar_pid != -1) {
          LOG("Sending SIGKILL (%d) to i3-nagbar with PID %d\n", SIGKILL, *nagbar_pid);
          kill(*nagbar_pid, SIGKILL);
      }
  }
  
  /*
   * Starts an i3-nagbar instance with the given parameters. Takes care of
   * handling SIGCHLD and killing i3-nagbar when i3 exits.
   *
   * The resulting PID will be stored in *nagbar_pid and can be used with
   * kill_nagbar() to kill the bar later on.
   *
   */
  void start_nagbar(pid_t *nagbar_pid, char *argv[]) {
      if (*nagbar_pid != -1) {
          DLOG("i3-nagbar already running (PID %d), not starting again.\n", *nagbar_pid);
          return;
      }
  
      *nagbar_pid = fork();
      if (*nagbar_pid == -1) {
          warn("Could not fork()");
          return;
      }
  
      /* child */
      if (*nagbar_pid == 0)
          exec_i3_utility("i3-nagbar", argv);
  
      DLOG("Starting i3-nagbar with PID %d\n", *nagbar_pid);
  
      /* parent */
      /* install a child watcher */
      ev_child *child = smalloc(sizeof(ev_child));
      ev_child_init(child, &nagbar_exited, *nagbar_pid, 0);
      child->data = nagbar_pid;
      ev_child_start(main_loop, child);
  
      /* install a cleanup watcher (will be called when i3 exits and i3-nagbar is
       * still running) */
      ev_cleanup *cleanup = smalloc(sizeof(ev_cleanup));
      ev_cleanup_init(cleanup, nagbar_cleanup);
      cleanup->data = nagbar_pid;
      ev_cleanup_start(main_loop, cleanup);
  }
  
  /*
   * Kills the i3-nagbar process, if *nagbar_pid != -1.
   *
   * If wait_for_it is set (restarting i3), this function will waitpid(),
   * otherwise, ev is assumed to handle it (reloading).
   *
   */
  void kill_nagbar(pid_t *nagbar_pid, bool wait_for_it) {
      if (*nagbar_pid == -1)
          return;
  
      if (kill(*nagbar_pid, SIGTERM) == -1)
          warn("kill(configerror_nagbar) failed");
  
      if (!wait_for_it)
          return;
  
      /* When restarting, we don’t enter the ev main loop anymore and after the
       * exec(), our old pid is no longer watched. So, ev won’t handle SIGCHLD
       * for us and we would end up with a <defunct> process. Therefore we
       * waitpid() here. */
      waitpid(*nagbar_pid, NULL, 0);
  }
  
  /*
   * Converts a string into a long using strtol().
   * This is a convenience wrapper checking the parsing result. It returns true
   * if the number could be parsed.
   */
  bool parse_long(const char *str, long *out, int base) {
      char *end = NULL;
      long result = strtol(str, &end, base);
      if (result == LONG_MIN || result == LONG_MAX || result < 0 || (end != NULL && *end != '\0')) {
          *out = result;
          return false;
      }
  
      *out = result;
      return true;
  }
  
  /*
   * Slurp reads path in its entirety into buf, returning the length of the file
   * or -1 if the file could not be read. buf is set to a buffer of appropriate
   * size, or NULL if -1 is returned.
   *
   */
  ssize_t slurp(const char *path, char **buf) {
      FILE *f;
      if ((f = fopen(path, "r")) == NULL) {
          ELOG("Cannot open file \"%s\": %s\n", path, strerror(errno));
          return -1;
      }
      struct stat stbuf;
      if (fstat(fileno(f), &stbuf) != 0) {
          ELOG("Cannot fstat() \"%s\": %s\n", path, strerror(errno));
          fclose(f);
          return -1;
      }
      /* Allocate one extra NUL byte to make the buffer usable with C string
       * functions. yajl doesn’t need this, but this makes slurp safer. */
      *buf = scalloc(stbuf.st_size + 1, 1);
      size_t n = fread(*buf, 1, stbuf.st_size, f);
      fclose(f);
      if ((ssize_t)n != stbuf.st_size) {
          ELOG("File \"%s\" could not be read entirely: got %zd, want %" PRIi64 "\n", path, n, (int64_t)stbuf.st_size);
          FREE(*buf);
          return -1;
      }
      return (ssize_t)n;
  }
  
  /*
   * Convert a direction to its corresponding orientation.
   *
   */
  orientation_t orientation_from_direction(direction_t direction) {
      return (direction == D_LEFT || direction == D_RIGHT) ? HORIZ : VERT;
  }
  
  /*
   * Convert a direction to its corresponding position.
   *
   */
  position_t position_from_direction(direction_t direction) {
      return (direction == D_LEFT || direction == D_UP) ? BEFORE : AFTER;
  }
  
  /*
   * Convert orientation and position to the corresponding direction.
   *
   */
  direction_t direction_from_orientation_position(orientation_t orientation, position_t position) {
      if (orientation == HORIZ) {
          return position == BEFORE ? D_LEFT : D_RIGHT;
      } else {
          return position == BEFORE ? D_UP : D_DOWN;
      }
  }
  