text: /* Miscellaneous program utilities. */
  
  #ifndef COMMON_H
  #define COMMON_H
  
  #include <stdio.h>
  
  
  /* Identifies game players. */
  typedef enum
  {
      PLAYER_X,
      PLAYER_O
  } Player;
  
  
  /* Returns 'X' for PLAYER_X, 'O' for PLAYER_O. */
  char playerToChar(Player player);
  
  /* Reads characters from a file until a given character is encountered.
     consume controls whether or not that character is consumed from the file.
     On success, returns 1.
     On error or EOF, returns 0. */
  int readUntil(FILE* file, char c, int consume);
  
  /* Checks if an entire string is whitespace.
     Empty string is considered to be all whitespace. */
  int isWhitespace(char const* str);
  
  
  #endif
  