+ mode = ((mode & R_OK ? 4 : 0)
+ + (mode & W_OK ? 2 : 0)
+ + (mode & X_OK ? 1 : 0));
+
+ if (mode == 0)
+ return 0; /* The file exists. */
+
+ /* Convert the file's permission bits to traditional form. */
+ if (S_IRUSR == (4 << 6) && S_IWUSR == (2 << 6) && S_IXUSR == (1 << 6)
+ && S_IRGRP == (4 << 3) && S_IWGRP == (2 << 3) && S_IXGRP == (1 << 3)
+ && S_IROTH == (4 << 0) && S_IWOTH == (2 << 0) && S_IXOTH == (1 << 0))
+ granted = stats.st_mode;
+ else
+ granted = ((stats.st_mode & S_IRUSR ? 4 << 6 : 0)
+ + (stats.st_mode & S_IWUSR ? 2 << 6 : 0)
+ + (stats.st_mode & S_IXUSR ? 1 << 6 : 0)
+ + (stats.st_mode & S_IRGRP ? 4 << 3 : 0)
+ + (stats.st_mode & S_IWGRP ? 2 << 3 : 0)
+ + (stats.st_mode & S_IXGRP ? 1 << 3 : 0)
+ + (stats.st_mode & S_IROTH ? 4 << 0 : 0)
+ + (stats.st_mode & S_IWOTH ? 2 << 0 : 0)
+ + (stats.st_mode & S_IXOTH ? 1 << 0 : 0));
+
+ if (euid == stats.st_uid)
+ granted >>= 6;
+ else if (egid == stats.st_gid || group_member (stats.st_gid))
+ granted >>= 3;
+
+ if ((mode & ~granted) == 0)