Add CL handling to hyc

This adds real command line handling to 'hyc' for issue #256

This fix catches missing/unreadable files and prints a nice
error message instead of a nasty stack trace when trying to
compile a non-existent file.

Also add this non-existent file check to hy to prevent the
current stack trace from something like "hy foobarbaz" when
"foobarbaz" doesn't exist.

also changes the failure return value to 2 to match Python.

hy/cmdline.py

@@ -248,7 +248,12 @@ def cmdline_handler(scriptname, argv):
 
         else:
             # User did "hy <filename>"
-            return run_file(options.args[0])
+            try:
+                return run_file(options.args[0])
+            except IOError as x:
+                sys.stderr.write("hy: Can't open file '%s': [Errno %d] %s\n" %
+                                 (x.filename, x.errno, x.strerror))
+                sys.exit(x.errno)
 
     # User did NOTHING!
     return run_repl()
@@ -262,4 +267,18 @@ def hy_main():
 # entry point for cmd line script "hyc"
 def hyc_main():
     from hy.importer import write_hy_as_pyc
-    write_hy_as_pyc(sys.argv[1])
+    parser = argparse.ArgumentParser(prog="hyc")
+    parser.add_argument("files", metavar="FILE", nargs='+',
+                        help="file to compile")
+    parser.add_argument("-v", action="version", version=VERSION)
+
+    options = parser.parse_args(sys.argv[1:])
+
+    for file in options.files:
+        try:
+            write_hy_as_pyc(file)
+            print("Compiling %s" % file)
+        except IOError as x:
+            sys.stderr.write("hyc: Can't open file '%s': [Errno %d] %s\n" %
+                             (x.filename, x.errno, x.strerror))
+            sys.exit(x.errno)

tests/test_bin.py

@@ -83,7 +83,7 @@ def test_bin_hy_file():
 
 def test_bin_hy_missing_file():
     ret = run_cmd("hy foobarbaz")
-    assert ret[0] == 1
+    assert ret[0] == 2
     assert "No such file" in ret[2]
 
 
@@ -102,6 +102,25 @@ def test_bin_hy_file_with_args():
     assert "foo" in ret[1]
 
 
+def test_bin_hyc():
+    ret = run_cmd("hyc")
+    assert ret[0] == 2
+    assert "usage" in ret[2]
+    ret = run_cmd("hyc -h")
+    assert ret[0] == 0
+    assert "usage" in ret[1]
+    ret = run_cmd("hyc tests/resources/argparse_ex.hy")
+    assert ret[0] == 0
+    assert "Compiling" in ret[1]
+    assert os.path.exists("tests/resources/argparse_ex.pyc")
+
+
+def test_bin_hyc_missing_file():
+    ret = run_cmd("hyc foobarbaz")
+    assert ret[0] == 2
+    assert "[Errno 2]" in ret[2]
+
+
 def test_hy2py():
     # XXX Astor doesn't seem to support Python3 :(
     if sys.version_info[0] == 3: