diff --git a/tqdm.1 b/tqdm.1
index 18484167..7da9a4b8 100644
--- a/tqdm.1
+++ b/tqdm.1
@@ -215,7 +215,15 @@ specified.
 .TP
 .B \-\-bytes=\f[I]bytes\f[]
 bool, optional.
-If true, will count bytes and ignore \f[C]delim\f[].
+If true, will count bytes, ignore \f[C]delim\f[], and default
+\f[C]unit_scale\f[] to True, \f[C]unit_divisor\f[] to 1024, and
+\f[C]unit\f[] to \[aq]B\[aq].
+.RS
+.RE
+.TP
+.B \-\-log=\f[I]log\f[]
+str, optional.
+CRITICAL|FATAL|ERROR|WARN(ING)|[default: \[aq]INFO\[aq]]|DEBUG|NOTSET.
 .RS
 .RE
 .SH AUTHORS
diff --git a/tqdm/_main.py b/tqdm/_main.py
index 3e9646b9..9c9273f6 100644
--- a/tqdm/_main.py
+++ b/tqdm/_main.py
@@ -2,10 +2,21 @@ from ._tqdm import tqdm, TqdmTypeError, TqdmKeyError
 from ._version import __version__  # NOQA
 import sys
 import re
+import logging
 __all__ = ["main"]
 
 
 def cast(val, typ):
+    log = logging.getLogger(__name__)
+    log.debug((val, typ))
+    if " or " in typ:
+        for t in typ.split(" or "):
+            try:
+                return cast(val, t)
+            except TqdmTypeError:
+                pass
+        raise TqdmTypeError(val + ' : ' + typ)
+
     # sys.stderr.write('\ndebug | `val:type`: `' + val + ':' + typ + '`.\n')
     if typ == 'bool':
         if (val == 'True') or (val == ''):
@@ -76,7 +87,7 @@ def posix_pipe(fin, fout, delim='\n', buf_size=256,
 
 
 # ((opt, type), ... )
-RE_OPTS = re.compile(r'\n {8}(\S+)\s{2,}:\s*([^\s,]+)')
+RE_OPTS = re.compile(r'\n {8}(\S+)\s{2,}:\s*([^,]+)')
 # better split method assuming no positional args
 RE_SHLEX = re.compile(r'\s*--?([^\s=]+)(?:\s*|=|$)')
 
@@ -87,6 +98,8 @@ UNSUPPORTED_OPTS = ('iterable', 'gui', 'out', 'file')
 CLI_EXTRA_DOC = r"""
         Extra CLI Options
         -----------------
+        name  : type, optional
+             TODO: find out why this is needed.
         delim  : chr, optional
             Delimiting character [default: '\n']. Use '\0' for null.
             N.B.: on Windows systems, Python converts '\n' to '\r\n'.
@@ -94,7 +107,10 @@ CLI_EXTRA_DOC = r"""
             String buffer size in bytes [default: 256]
             used when `delim` is specified.
         bytes  : bool, optional
-            If true, will count bytes and ignore `delim`.
+            If true, will count bytes, ignore `delim`, and default
+            `unit_scale` to True, `unit_divisor` to 1024, and `unit` to 'B'.
+        log  : str, optional
+            CRITICAL|FATAL|ERROR|WARN(ING)|[default: 'INFO']|DEBUG|NOTSET.
 """
 
 
@@ -104,13 +120,27 @@ def main(fp=sys.stderr):
     ---------
     fp  : file-like object for tqdm
     """
+    try:
+        log = sys.argv.index('--log')
+    except ValueError:
+        logLevel = 'INFO'
+    else:
+        # sys.argv.pop(log)
+        # logLevel = sys.argv.pop(log)
+        logLevel = sys.argv[log + 1]
+    logging.basicConfig(level=getattr(logging, logLevel))
+    log = logging.getLogger(__name__)
+
     d = tqdm.__init__.__doc__ + CLI_EXTRA_DOC
 
     opt_types = dict(RE_OPTS.findall(d))
+    # opt_types['delim'] = 'chr'
 
     for o in UNSUPPORTED_OPTS:
         opt_types.pop(o)
 
+    log.debug(sorted(opt_types.items()))
+
     # d = RE_OPTS.sub(r'  --\1=<\1>  : \2', d)
     split = RE_OPTS.split(d)
     opt_types_desc = zip(split[1::3], split[2::3], split[3::3])
@@ -137,6 +167,9 @@ Options:
     argv = RE_SHLEX.split(' '.join(["tqdm"] + sys.argv[1:]))
     opts = dict(zip(argv[1::2], argv[2::2]))
 
+    log.debug(opts)
+    opts.pop('log', True)
+
     tqdm_args = {'file': fp}
     try:
         for (o, v) in opts.items():
@@ -144,7 +177,7 @@ Options:
                 tqdm_args[o] = cast(v, opt_types[o])
             except KeyError as e:
                 raise TqdmKeyError(str(e))
-        # fp.write('\ndebug | args: ' + str(tqdm_args) + '\n')
+        log.debug('args:' + str(tqdm_args))
     except:
         fp.write('\nError:\nUsage:\n  tqdm [--help | options]\n')
         for i in sys.stdin:
@@ -155,13 +188,19 @@ Options:
         delim = tqdm_args.pop('delim', '\n')
         delim_per_char = tqdm_args.pop('bytes', False)
         if delim_per_char:
+            tqdm_args.setdefault('unit', 'B')
+            tqdm_args.setdefault('unit_scale', True)
+            tqdm_args.setdefault('unit_divisor', 1024)
+            log.debug(tqdm_args)
             with tqdm(**tqdm_args) as t:
                 posix_pipe(sys.stdin, sys.stdout,
                            '', buf_size, t.update)
         elif delim == '\n':
+            log.debug(tqdm_args)
             for i in tqdm(sys.stdin, **tqdm_args):
                 sys.stdout.write(i)
         else:
+            log.debug(tqdm_args)
             with tqdm(**tqdm_args) as t:
                 posix_pipe(sys.stdin, sys.stdout,
                            delim, buf_size, t.update)
diff --git a/tqdm/tests/tests_main.py b/tqdm/tests/tests_main.py
index 32dc8205..0781c242 100644
--- a/tqdm/tests/tests_main.py
+++ b/tqdm/tests/tests_main.py
@@ -2,7 +2,8 @@ import sys
 import subprocess
 from tqdm import main, TqdmKeyError, TqdmTypeError
 
-from tests_tqdm import with_setup, pretest, posttest, _range, closing, UnicodeIO
+from tests_tqdm import with_setup, pretest, posttest, _range, closing, \
+    UnicodeIO, StringIO
 
 
 def _sh(*cmd, **kwargs):
@@ -28,7 +29,7 @@ def test_main():
     # semi-fake test which gets coverage:
     _SYS = sys.stdin, sys.argv
 
-    with closing(UnicodeIO()) as sys.stdin:
+    with closing(StringIO()) as sys.stdin:
         sys.argv = ['', '--desc', 'Test CLI delims',
                     '--ascii', 'True', '--delim', r'\0', '--buf_size', '64']
         sys.stdin.write('\0'.join(map(str, _range(int(1e3)))))
@@ -42,10 +43,10 @@ def test_main():
     import tqdm.__main__  # NOQA
 
     IN_DATA = '\0'.join(IN_DATA_LIST)
-    with closing(UnicodeIO()) as sys.stdin:
+    with closing(StringIO()) as sys.stdin:
         sys.stdin.write(IN_DATA)
         sys.stdin.seek(0)
-        sys.argv = ['', '--ascii', '--bytes']
+        sys.argv = ['', '--ascii', '--bytes', '--unit_scale', 'False']
         with closing(UnicodeIO()) as fp:
             main(fp=fp)
             assert (str(len(IN_DATA)) in fp.getvalue())