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).
   *
   */
  #pragma once
  
  #include <config.h>
  
  #include <err.h>
  
  #include "data.h"
  
  #define die(...) errx(EXIT_FAILURE, __VA_ARGS__);
  #define exit_if_null(pointer, ...) \
      {                              \
          if (pointer == NULL)       \
              die(__VA_ARGS__);      \
      }
  #define STARTS_WITH(string, needle) (strncasecmp((string), (needle), strlen((needle))) == 0)
  #define CIRCLEQ_NEXT_OR_NULL(head, elm, field) (CIRCLEQ_NEXT(elm, field) != CIRCLEQ_END(head) ? CIRCLEQ_NEXT(elm, field) : NULL)
  #define CIRCLEQ_PREV_OR_NULL(head, elm, field) (CIRCLEQ_PREV(elm, field) != CIRCLEQ_END(head) ? CIRCLEQ_PREV(elm, field) : NULL)
  #define FOR_TABLE(workspace)                             \
      for (int cols = 0; cols < (workspace)->cols; cols++) \
          for (int rows = 0; rows < (workspace)->rows; rows++)
  
  #define NODES_FOREACH(head)                                                    \
      for (Con *child = (Con *)-1; (child == (Con *)-1) && ((child = 0), true);) \
      TAILQ_FOREACH(child, &((head)->nodes_head), nodes)
  
  #define NODES_FOREACH_REVERSE(head)                                            \
      for (Con *child = (Con *)-1; (child == (Con *)-1) && ((child = 0), true);) \
      TAILQ_FOREACH_REVERSE(child, &((head)->nodes_head), nodes_head, nodes)
  
  /* greps the ->nodes of the given head and returns the first node that matches the given condition */
  #define GREP_FIRST(dest, head, condition) \
      NODES_FOREACH(head) {                 \
          if (!(condition))                 \
              continue;                     \
                                            \
          (dest) = child;                   \
          break;                            \
      }
  
  #define FREE(pointer)   \
      do {                \
          free(pointer);  \
          pointer = NULL; \
      } while (0)
  
  #define CALL(obj, member, ...) obj->member(obj, ##__VA_ARGS__)
  
  #define SWAP(first, second, type) \
      do {                          \
          type tmp_SWAP = first;    \
          first = second;           \
          second = tmp_SWAP;        \
      } while (0)
  
  int min(int a, int b);
  int max(int a, int b);
  bool rect_contains(Rect rect, uint32_t x, uint32_t y);
  Rect rect_add(Rect a, Rect b);
  Rect rect_sub(Rect a, Rect b);
  
  /**
   * Returns true if the name consists of only digits.
   *
   */
  __attribute__((pure)) bool name_is_digits(const char *name);
  
  /**
   * 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);
  
  /**
   * Parses the workspace name as a number. Returns -1 if the workspace should be
   * interpreted as a "named workspace".
   *
   */
  long ws_name_to_number(const char *name);
  
  /**
   * 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);
  
  /**
   * 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[]);
  
  /**
   * Checks if the given path exists by calling stat().
   *
   */
  bool path_exists(const char *path);
  
  /**
   * Restart i3 in-place
   * appends -a to argument list to disable autostart
   *
   */
  void i3_restart(bool forget_layout);
  
  #if defined(__OpenBSD__) || defined(__APPLE__)
  
  /*
   * Taken from FreeBSD
   * Find the first occurrence of the byte string s in byte string l.
   *
   */
  void *memmem(const void *l, size_t l_len, const void *s, size_t s_len);
  
  #endif
  
  /**
   * 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);
  
  /**
   * 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[]);
  
  /**
   * 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);
  
  /**
   * 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);
  
  /**
   * 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);
  