diff --git a/md_pdf/build/cli.py b/md_pdf/build/cli.py
index 4c68dd7..0eb2ee2 100644
--- a/md_pdf/build/cli.py
+++ b/md_pdf/build/cli.py
@@ -1,5 +1,9 @@
 import click
+from md_pdf.build.md import read_files
 
 @click.command('build', short_help="Build document")
-def cli():
-    pass
+@click.argument('in_files', type=click.Path(dir_okay=False, resolve_path=True, writable=True), nargs=-1)
+@click.option('--output', '-o', type=click.Path(file_okay=False, resolve_path=True, writable=True), default='out/')
+def cli(in_files, output):
+    data = read_files(in_files)
+    print(data)
diff --git a/md_pdf/build/md.py b/md_pdf/build/md.py
index 07188ad..fb92365 100644
--- a/md_pdf/build/md.py
+++ b/md_pdf/build/md.py
@@ -6,6 +6,5 @@ def get_files_content(filenames):
             yield f.read()
 
 
-def read_files(files_glob):
-    filenames = glob.glob(files_glob)
+def read_files(filenames):
     return '\n'.join(list(get_files_content(filenames)))
diff --git a/md_pdf/cli.py b/md_pdf/cli.py
index 361593e..facb294 100644
--- a/md_pdf/cli.py
+++ b/md_pdf/cli.py
@@ -23,8 +23,9 @@ class MDPDFCLI(click.MultiCommand):
                 code = compile(f.read(), fn, 'exec')
                 eval(code, ns, ns)
             return ns['cli']
-        except:
-            return
+        except Exception as e:
+            print("An Error Occured:s")
+            raise e
 
 
 cli = MDPDFCLI(help='This tool\'s subcommands are loaded from a plugin folder dynamically.')