diff --git a/linenumbers.py b/linenumbers.py
index 5715723..c9c3186 100644
--- a/linenumbers.py
+++ b/linenumbers.py
@@ -1,12 +1,28 @@
+import argparse
 import sys
 
-from voussoirkit import clipext
+from voussoirkit import pipeable
 
-if len(sys.argv) == 1:
-    sys.argv.append('!i')
-text = clipext.resolve(sys.argv[1])
-lines = text.splitlines()
-digits = len(str(len(lines)))
-form = '{no:>0%d} | {line}' % digits
-for (index, line) in enumerate(lines):
-    print(form.format(no=index+1, line=line))
+def linenumbers_argparse(args):
+    lines = pipeable.input(args.source, read_files=True)
+    if args.lazy:
+        form = '{no} | {line}'
+    else:
+        lines = list(lines)
+        digits = len(str(len(lines)))
+        form = '{no:>0%d} | {line}' % digits
+    for (index, line) in enumerate(lines):
+        print(form.format(no=index+1, line=line))
+
+def main(argv):
+    parser = argparse.ArgumentParser(description=__doc__)
+
+    parser.add_argument('source')
+    parser.add_argument('--lazy', dest='lazy', action='store_true')
+    parser.set_defaults(func=linenumbers_argparse)
+
+    args = parser.parse_args(argv)
+    return args.func(args)
+
+if __name__ == '__main__':
+    raise SystemExit(main(sys.argv[1:]))