diff --git a/Makefile b/Makefile
index 7eb6e35..6fe9a6f 100644
--- a/Makefile
+++ b/Makefile
@@ -9,10 +9,10 @@ CC=cc
 CFLAGS=-I$(IDIR) -Wall -Wextra -pedantic
 LIB=
 
-_DEPS=
+_DEPS=lib.h
 DEPS=$(patsubst %,$(IDIR)/%,$(_DEPS))
 
-_OBJ=$(NAME).o
+_OBJ=$(NAME).o lib.o
 OBJ=$(patsubst %,$(ODIR)/%,$(_OBJ))
 
 
diff --git a/compile_flags.txt b/compile_flags.txt
new file mode 100644
index 0000000..30679be
--- /dev/null
+++ b/compile_flags.txt
@@ -0,0 +1 @@
+-Iinclude
diff --git a/include/lib.h b/include/lib.h
new file mode 100644
index 0000000..69b5019
--- /dev/null
+++ b/include/lib.h
@@ -0,0 +1,4 @@
+#ifndef LIB_H
+#define LIB_H
+void die(const char *message);
+#endif
diff --git a/src/lib.c b/src/lib.c
new file mode 100644
index 0000000..ef92935
--- /dev/null
+++ b/src/lib.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void die(const char *message) {
+  perror(message);
+  exit(1);
+}
diff --git a/src/main.c b/src/main.c
index 03b2213..d038256 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,3 +1,21 @@
-int main(void) {
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "lib.h"
+
+int main(int argc, char *argv[]) {
+  if (argc < 2) {
+    printf("usage: catclone <FILE>\n");
+    die("args");
+  }
+
+  FILE *fp = fopen(argv[1], "r");
+
+  if (fp == NULL) {
+    die("fopen");
+  }
+
+  fclose(fp);
+
   return 0;
 }