miniterm: add "hexlify" codec

the hexlify codec can send and receive hex encoded data and converts bytes to strings (unlike the built-in hex code)
try it with --encoding hexlify

2 files changed, 88 insertions, 0 deletions

diff --git a/serial/tools/hexlify_codec.py b/serial/tools/hexlify_codec.py
new file mode 100644
index 0000000..f3ba04f
--- /dev/null
+++ b/serial/tools/hexlify_codec.py
@@ -0,0 +1,82 @@
+"""\
+Python 'hex' Codec - 2-digit hex with spaces content transfer encoding.
+"""
+
+import codecs
+import serial
+
+HEXDIGITS = '0123456789ABCDEF'
+
+### Codec APIs
+
+def hex_encode(input, errors='strict'):
+    return (serial.to_bytes([int(h, 16) for h in input.split()]), len(input))
+
+def hex_decode(input, errors='strict'):
+    return (''.join('{:02X} '.format(b) for b in input), len(input))
+
+class Codec(codecs.Codec):
+    def encode(self, input, errors='strict'):
+        return serial.to_bytes([int(h, 16) for h in input.split()])
+    def decode(self, input, errors='strict'):
+        return ''.join('{:02X} '.format(b) for b in input)
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+
+    def __init__(self, errors='strict'):
+        self.errors = errors
+        self.state = 0
+
+    def reset(self):
+        self.state = 0
+
+    def getstate(self):
+        return self.state
+
+    def setstate(self, state):
+        self.state = state
+
+    def encode(self, input, final=False):
+        state = self.state
+        encoded = []
+        for c in input.upper():
+            if c in HEXDIGITS:
+                z = HEXDIGITS.index(c)
+                if state:
+                    encoded.append(z + (state & 0xf0))
+                    state = 0
+                else:
+                    state = 0x100 + (z << 4)
+            elif c == ' ':      # allow spaces to separate values
+                if state and self.errors == 'strict':
+                    raise UnicodeError('odd number of hex digits')
+                state = 0
+            else:
+                if self.errors == 'strict':
+                    raise UnicodeError('non-hex digit found: %r' % c)
+        self.state = state
+        return serial.to_bytes(encoded)
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input, final=False):
+        return ''.join('{:02X} '.format(b) for b in input)
+
+class StreamWriter(Codec, codecs.StreamWriter):
+    pass
+
+class StreamReader(Codec, codecs.StreamReader):
+    pass
+
+### encodings module API
+
+def getregentry():
+    return codecs.CodecInfo(
+        name='hexlify',
+        encode=hex_encode,
+        decode=hex_decode,
+        incrementalencoder=IncrementalEncoder,
+        incrementaldecoder=IncrementalDecoder,
+        streamwriter=StreamWriter,
+        streamreader=StreamReader,
+        _is_text_encoding=True,
+    )
diff --git a/serial/tools/miniterm.py b/serial/tools/miniterm.py
index cb60a2b..e56e4cc 100644
--- a/serial/tools/miniterm.py
+++ b/serial/tools/miniterm.py
@@ -20,6 +20,9 @@ except NameError:
     raw_input = input   # in python3 it's "raw"
     unichr = chr
 
+from . import hexlify_codec
+codecs.register(lambda c: hexlify_codec.getregentry() if c == 'hexlify' else None)
+
 
 def key_description(character):
     """generate a readable description for a key"""
@@ -198,6 +201,7 @@ class NoControls(NoTerminal):
 
 class Printable(Transform):
     """Show decimal code for all non-ASCII characters and replace most control codes"""
+
     def rx(self, text):
         r = []
         for t in text:
@@ -215,6 +219,7 @@ class Printable(Transform):
 
 class Colorize(Transform):
     """Apply different colors for received and echo"""
+
     def __init__(self):
         # XXX make it configurable, use colorama?
         self.input_color = '\x1b[37m'
@@ -229,6 +234,7 @@ class Colorize(Transform):
 
 class DebugIO(Transform):
     """Print what is sent and received"""
+
     def rx(self, text):
         sys.stderr.write(' [RX:{}] '.format(repr(text)))
         sys.stderr.flush()