Add option to force DTS and RTS pins high

This is for development boards like those for the ESP32, where it's
common to use RTS and DTR to control chip resets.

TODO.md

@@ -0,0 +1,13 @@
+- serial.write() may block for reasons beyond our control.  For
+  example, CDC-ACM devices may do flow control internally and block on
+  USB transfers; the CDC-ACM interface does not expose flow control
+  settings to the PC, and writes will hang indefinitely even if
+  --flow is not used.  Since polling the keyboard is in the write loop,
+  this kills us.
+
+- Support some other escape character so ^C can be optionally used.
+  Maybe even remove ^C as an option, use ^] exclusively?
+
+- Support reconnection
+
+- See patches from "Guyzmo"

terminal.py

@@ -21,17 +21,22 @@ import threading
 import traceback
 import time
 import signal
+import fcntl
+import string
+import re
 
 # Need OS-specific method for getting keyboard input.
 if os.name == 'nt':
     import msvcrt
     class Console:
-        def __init__(self):
+        def __init__(self, bufsize = 1):
-            pass
+            # Buffer size > 1 not supported on Windows
+            self.tty = True
         def cleanup(self):
             pass
         def getkey(self):
-            while 1:
+            start = time.time()
+            while True:
                 z = msvcrt.getch()
                 if z == '\0' or z == '\xe0': # function keys
                     msvcrt.getch()
@@ -39,37 +44,58 @@ if os.name == 'nt':
                     if z == '\r':
                         return '\n'
                     return z
+                if (time.time() - start) > 0.1:
+                    return None
+
+    class MySerial(serial.Serial):
+        def nonblocking_read(self, size=1):
+            # Buffer size > 1 not supported on Windows
+            return self.read(1)
 elif os.name == 'posix':
-    import termios, select
+    import termios, select, errno
     class Console:
-        def __init__(self):
+        def __init__(self, bufsize = 65536):
+            self.bufsize = bufsize
             self.fd = sys.stdin.fileno()
-            try:
+            if os.isatty(self.fd):
+                self.tty = True
                 self.old = termios.tcgetattr(self.fd)
                 tc = termios.tcgetattr(self.fd)
                 tc[3] = tc[3] & ~termios.ICANON & ~termios.ECHO & ~termios.ISIG
                 tc[6][termios.VMIN] = 1
                 tc[6][termios.VTIME] = 0
                 termios.tcsetattr(self.fd, termios.TCSANOW, tc)
-            except termios.error:
+            else:
-                # ignore errors, so we can pipe stuff to this script
+                self.tty = False
-                pass
         def cleanup(self):
-            try:
+            if self.tty:
                 termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.old)
-            except:
-                # ignore errors, so we can pipe stuff to this script
-                pass
         def getkey(self):
             # Return -1 if we don't get input in 0.1 seconds, so that
             # the main code can check the "alive" flag and respond to SIGINT.
             [r, w, x] = select.select([self.fd], [], [self.fd], 0.1)
             if r:
-                return os.read(self.fd, 1)
+                return os.read(self.fd, self.bufsize)
             elif x:
                 return ''
             else:
-                return -1
+                return None
+
+    class MySerial(serial.Serial):
+        def nonblocking_read(self, size=1):
+            [r, w, x] = select.select([self.fd], [], [self.fd], self._timeout)
+            if r:
+                try:
+                    return os.read(self.fd, size)
+                except OSError as e:
+                    if e.errno == errno.EAGAIN:
+                        return None
+                    raise
+            elif x:
+                raise SerialException("exception (device disconnected?)")
+            else:
+                return None # timeout
+
 else:
     raise ("Sorry, no terminal implementation for your platform (%s) "
            "available." % sys.platform)
@@ -104,33 +130,44 @@ class Jimterm:
                  suppress_read_firstnull = True,
                  transmit_all = False,
                  add_cr = False,
-                 raw = False,
+                 send_cr = False,
-                 color = True):
+                 raw = True,
+                 color = True,
+                 bufsize = 65536):
 
         self.color = JimtermColor()
         if color:
             self.color.setup(len(serials))
 
         self.serials = serials
-        self.suppress_write_bytes = suppress_write_bytes or ""
+        self.suppress_write_bytes = suppress_write_bytes
         self.suppress_read_firstnull = suppress_read_firstnull
         self.last_color = ""
         self.threads = []
         self.transmit_all = transmit_all
         self.add_cr = add_cr
+        self.send_cr = send_cr
         self.raw = raw
+        self.bufsize = bufsize
+        self.quote_re = None
+        self.output_lock = threading.Lock()
 
-    def print_header(self, nodes, bauds):
+    def print_header(self, nodes, bauds, output = sys.stdout):
         for (n, (node, baud)) in enumerate(zip(nodes, bauds)):
-            print (self.color.code(n)
+            output.write(self.color.code(n)
-                   + node + ", " + str(baud) + " baud"
+                         + node + ", " + str(baud) + " baud"
-                   + self.color.reset)
+                         + self.color.reset + "\n")
-        print "^C to exit"
+        if sys.stdin.isatty():
-        print "----------"
+            output.write("^C to exit\n")
+            output.write("----------\n")
+        output.flush()
 
     def start(self):
         self.alive = True
 
+        # Set up console
+        self.console = Console(self.bufsize)
+
         # serial->console, all devices
         for (n, serial) in enumerate(self.serials):
             self.threads.append(threading.Thread(
@@ -139,7 +176,6 @@ class Jimterm:
                 ))
 
         # console->serial
-        self.console = Console()
         self.threads.append(threading.Thread(target = self.writer))
 
         # start all threads
@@ -155,91 +191,128 @@ class Jimterm:
             while thread.isAlive():
                 thread.join(0.1)
 
+    def quote_raw(self, data):
+        if self.quote_re is None:
+            matcher = '[^%s]' % re.escape(string.printable + "\b")
+            if sys.version_info < (3,):
+                self.quote_re = re.compile(matcher)
+                qf = lambda x: ("\\x%02x" % ord(x.group(0)))
+            else:
+                self.quote_re = re.compile(matcher.encode('ascii'))
+                qf = lambda x: ("\\x%02x" % ord(x.group(0))).encode('ascii')
+            self.quote_func = qf
+        return self.quote_re.sub(self.quote_func, data)
+
     def reader(self, serial, color):
         """loop and copy serial->console"""
         first = True
         try:
+            if (sys.version_info < (3,)):
+                null = '\x00'
+            else:
+                null = b'\x00'
             while self.alive:
-                data = serial.read(1)
+                data = serial.nonblocking_read(self.bufsize)
-                if not data:
+                if data is None:
                     continue
+                if not len(data):
+                    raise Exception("read returned EOF")
 
                 # don't print a NULL if it's the first character we
                 # read.  This hides startup/port-opening glitches with
                 # some serial devices.
-                if self.suppress_read_firstnull and first and data == '\0':
+                if self.suppress_read_firstnull and first and data[0] == null:
                     first = False
-                    continue
+                    data = data[1:]
                 first = False
 
+                self.output_lock.acquire()
+
                 if color != self.last_color:
                     self.last_color = color
-                    sys.stdout.write(color)
+                    os.write(sys.stdout.fileno(), color)
 
-                if (self.raw or
+                if self.add_cr:
-                    (ord(data) >= 32 and ord(data) < 128) or
+                    if sys.version_info < (3,):
-                    data == '\r' or data == '\n' or data == '\t'):
+                        data = data.replace('\n', '\r\n')
-                    if self.add_cr and data == '\n':
-                        sys.stdout.write('\r' + data)
                     else:
-                        sys.stdout.write(data)
+                        data = data.replace(b'\n', b'\r\n')
-                else:
+
-                    sys.stdout.write('\\x'+("0"+hex(ord(data))[2:])[-2:])
+                if not self.raw:
+                    data = self.quote_raw(data)
+
+                os.write(sys.stdout.fileno(), data)
+
+                self.output_lock.release()
 
-                sys.stdout.flush()
         except Exception as e:
+            self.console.cleanup()
             sys.stdout.write(color)
             sys.stdout.flush()
             traceback.print_exc()
             sys.stdout.write(self.color.reset)
             sys.stdout.flush()
-            self.console.cleanup()
             os._exit(1)
 
     def writer(self):
         """loop and copy console->serial until ^C"""
         try:
+            if (sys.version_info < (3,)):
+                ctrlc = '\x03'
+            else:
+                ctrlc = b'\x03'
             while self.alive:
                 try:
                     c = self.console.getkey()
                 except KeyboardInterrupt:
-                    c = '\x03'
-                if c == '\x03':
                     self.stop()
                     return
-                elif c == -1:
+                if c is None:
-                    # No input, try again
+                    # No input, try again.
                     continue
+                elif self.console.tty and ctrlc in c:
+                    # Try to catch ^C that didn't trigger KeyboardInterrupt
+                    self.stop()
+                    return
                 elif c == '':
-                    # EOF on input.  Wait a tiny bit so we can
+                    # Probably EOF on input.  Wait a tiny bit so we can
                     # flush the remaining input, then stop.
                     time.sleep(0.25)
                     self.stop()
                     return
-                elif c in self.suppress_write_bytes:
-                    # Don't send these bytes
-                    continue
                 else:
-                    # send character
+                    # Remove bytes we don't want to send
+                    if self.suppress_write_bytes is not None:
+                        c = c.translate(None, self.suppress_write_bytes)
+
+                    if self.send_cr and c == '\n':
+                            c = '\r'
+                    # Send character
                     if self.transmit_all:
                         for serial in self.serials:
                             serial.write(c)
                     else:
                         self.serials[0].write(c)
         except Exception as e:
+            self.console.cleanup()
             sys.stdout.write(self.color.reset)
             sys.stdout.flush()
             traceback.print_exc()
-            self.console.cleanup()
             os._exit(1)
 
     def run(self):
         # Set all serial port timeouts to 0.1 sec
         saved_timeouts = []
-        for (n, serial) in enumerate(self.serials):
+        for serial in self.serials:
             saved_timeouts.append(serial.timeout)
             serial.timeout = 0.1
 
+        # Work around https://sourceforge.net/p/pyserial/bugs/151/
+        saved_writeTimeouts = []
+        for serial in self.serials:
+            saved_writeTimeouts.append(serial.writeTimeout)
+            serial.writeTimeout = 1000000
+
         # Handle SIGINT gracefully
         signal.signal(signal.SIGINT, lambda *args: self.stop())
 
@@ -248,11 +321,13 @@ class Jimterm:
         self.join()
 
         # Restore serial port timeouts
-        for (n, serial) in enumerate(self.serials):
+        for (serial, saved) in zip(self.serials, saved_timeouts):
-            serial.timeout = saved_timeouts[n]
+            serial.timeout = saved
+        for (serial, saved) in zip(self.serials, saved_writeTimeouts):
+            serial.writeTimeout = saved
 
         # Cleanup
-        print self.color.reset # and a newline
+        sys.stdout.write(self.color.reset + "\n")
         self.console.cleanup()
 
 if __name__ == "__main__":
@@ -272,23 +347,42 @@ if __name__ == "__main__":
                         "per-device baudrates.")
 
     parser.add_argument("--quiet", "-q", action="store_true",
-                        help="Less verbose output (omit header)")
+                        help="Don't print header")
+
     parser.add_argument("--baudrate", "-b", metavar="BAUD", type=int,
                         help="Default baudrate for all devices", default=115200)
     parser.add_argument("--crlf", "-c", action="store_true",
                         help="Add CR before incoming LF")
+    parser.add_argument("--lfcr", "-C", action="store_true",
+                        help="Send CR instead of LF on output")
     parser.add_argument("--all", "-a", action="store_true",
                         help="Send keystrokes to all devices, not just "
                         "the first one")
     parser.add_argument("--mono", "-m", action="store_true",
                         help="Don't use colors in output")
-    parser.add_argument("--raw", "-r", action="store_true",
-                        help="Don't escape unprintable characters")
     parser.add_argument("--flow", "-f", action="store_true",
                         help="Enable RTS/CTS flow control")
+    parser.add_argument("--esp", "-e", action="store_true",
+                        help="Force RTS and DTR high, for ESP boards. Note that"
+                        " the lines may still glitch low at startup.")
+    parser.add_argument("--bufsize", "-z", metavar="SIZE", type=int,
+                        help="Buffer size for reads and writes", default=65536)
+
+    group = parser.add_mutually_exclusive_group(required = False)
+    group.add_argument("--raw", "-r", action="store_true",
+                       default=argparse.SUPPRESS,
+                       help="Output characters directly "
+                       "(default, if stdout is not a tty)")
+    group.add_argument("--no-raw", "-R", action="store_true",
+                       default=argparse.SUPPRESS,
+                       help="Quote unprintable characters "
+                       "(default, if stdout is a tty)")
 
     args = parser.parse_args()
 
+    piped = not sys.stdout.isatty()
+    raw = "raw" in args or (piped and "no_raw" not in args)
+
     devs = []
     nodes = []
     bauds = []
@@ -304,7 +398,13 @@ if __name__ == "__main__":
             sys.stderr.write("error: %s specified more than once\n" % node)
             raise SystemExit(1)
         try:
-            dev = serial.Serial(node, baud, rtscts = args.flow)
+            dev = MySerial(None, baud, rtscts = args.flow)
+            dev.port = node
+            if args.esp:
+                # Force DTR and RTS high by setting to false
+                dev.dtr = False
+                dev.rts = False
+            dev.open()
         except serial.serialutil.SerialException:
             sys.stderr.write("error opening %s\n" % node)
             raise SystemExit(1)
@@ -315,8 +415,11 @@ if __name__ == "__main__":
     term = Jimterm(devs,
                    transmit_all = args.all,
                    add_cr = args.crlf,
-                   raw = args.raw,
+                   send_cr = args.lfcr,
-                   color = (os.name == "posix" and not args.mono))
+                   raw = raw,
+                   color = (os.name == "posix" and not args.mono),
+                   bufsize = args.bufsize)
     if not args.quiet:
-        term.print_header(nodes, bauds)
+        term.print_header(nodes, bauds, sys.stderr)
+
     term.run()