Add test implementation to main file

main.c

@@ -1,8 +1,156 @@
+#include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
 #include "board.h"
 
+struct board_file
+{
+  int fd;
+  void *data;
+};
+
+
+/**
+ * Determines if the given char is a valid character for defining
+ * a board element
+ */
+static inline bool
+is_valid_def (char def)
+{
+  return  def == ' '    ||
+          (
+            def >= '0'  &&
+            def <= '9'
+          );
+}
+
+/**
+ * Load a board-definition file and return file descriptor
+ */
+static struct board_file
+load_board_file (const char *path)
+{
+  struct board_file file;
+  file.fd = -1;
+  file.data = NULL;
+
+  /* Open file */
+  int fd = open (path, 0);
+  if (fd < 0)
+    return file;
+
+  /* Map 89 bytes of file to memory */
+  void *region = mmap (NULL, 89, PROT_READ, MAP_SHARED, fd, 0);
+  if (region == -1)
+  {
+    close (fd);
+    return file;
+  }
+
+  /*
+    Ensure data in file is formatted correctly:
+      1) Every 10th character is ignored (row-terminator)
+      2) Each character must be in range '0'-'9' or ' '
+  */
+  char *data = region;
+  for (unsigned i = 1; i <= 89; ++i)
+    if (!((i % 10) == 0) && !is_valid_def (data[i - 1]))
+    {
+      munmap (region, 89);
+      close (fd);
+      return file;
+    }
+
+  /* Save file data to struct and return */
+  file.fd = fd;
+  file.data = region;
+
+  return file;
+}
+
+/**
+ * Free all resources linked to an opened board definition file
+ */
+static void
+close_board_file (struct board_file file)
+{
+  close (file.fd);
+  munmap (file.data, 89);
+}
+
+static void
+copy_to_board (struct board_file file, struct board *board)
+{
+  // Clear board
+  board_init (board);
+
+  char *data = file.data;
+  for (unsigned i = 1; i <= 89; ++i)
+    if ((i % 10) != 0)
+    {
+      board_pos x = i % 10;
+      board_pos y = i / 10;
+
+      if (data[i - 1] != ' ')
+        board_set (board, x - 1, y, data[i - 1] - '0' - 1);
+    }
+}
+
+static void
+print_board (struct board *board)
+{
+  for (board_pos y = 0; y < 9; ++y)
+  {
+    /* Print row */
+    for (board_pos x = 0; x < 9; ++x)
+    {
+      /* Print board element */
+      if (board_has_value (board, x, y))
+        printf ("%u", board_get_value (board, x, y) + 1);
+      else
+        fputs (" ", stdout);
+
+      /* Print column element delimiter */
+      if (x < 8)
+        fputs("|", stdout);
+    }
+    
+    fputs("\n", stdout);
+    
+    /* Print row element delimiter */
+    if (y < 8)
+    {
+      for (board_pos x = 0; x < 17; ++x)
+      {
+        if ((x & 1) == 0)
+          fputs ("-", stdout);
+        else
+          fputs ("+", stdout);
+      }
+      fputs ("\n", stdout);
+    }
+  }
+}
+
 int
 main (int argc, char **argv, char **env)
 {
+  if (argc != 2) return -1;
+  
+  struct board_file file = load_board_file (argv[1]);
+  if (file.fd == -1 || file.data == NULL)
+    return -1;
+
+  struct board board;
+  copy_to_board (file, &board);
+
+  close_board_file (file);
+
+  print_board (&board);
+
   return 0;
 }