Fixes for linux

src/main.c

@@ -23,11 +23,14 @@
 #  include "config.h"
 #endif
 
+#include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <pthread.h>
+#include <unistd.h>
 
 #include <sys/stat.h>
 #include <sys/types.h>