gpscat

   1 #!/usr/bin/env python
   2 #
   3 # This file is Copyright (c) 2010 by the GPSD project
   4 # BSD terms apply: see the file COPYING in the distribution root for details.
   5 #
   6 # Display GPS output.  Hexify it if necessary.
   7 #
   8 import os, sys, termios, socket, select, getopt, curses.ascii
   9 import gps.packet as sniffer
  10
  11 # The spec says 82, but some receivers (TN-200, GSW 2.3.2) output 86 characters
  12 NMEA_MAX = 86
  13
  14 # Lowest debug level at which packet getter begins to emit messages, minus one
  15 BASELEVEL = sniffer.LOG_IO
  16
  17 highhalf_latch = True
  18
  19 def hexdump(str):
  20     dmp = ""
  21     for (i, ch) in enumerate(str):
  22         if curses.ascii.isprint(ord(ch)) or curses.ascii.isspace(ord(ch)):
  23             dmp += ch
  24         else:
  25             dmp += "\\x%02x" % ord(ch)
  26     return dmp
  27
  28 debuglevel = 0
  29
  30 def reporter(errlevel, msg):
  31     if errlevel <= debuglevel:
  32         sys.stdout.write(msg)
  33
  34 if __name__ == '__main__':
  35     buf = ""
  36     try:
  37         try:
  38             (options, arguments) = getopt.getopt(sys.argv[1:], "hps:tD:V")
  39         except getopt.GetoptError, msg:
  40             print "gpscat: " + str(msg)
  41             raise SystemExit, 1
  42
  43         speed = None
  44         parity = None
  45         stopbits = None
  46         rawmode = True
  47         typeflag = False
  48         for (switch, val) in options:
  49             if switch == '-p':
  50                 rawmode = False
  51             elif switch == '-s':
  52                 if val[-2] in ('N', 'E', 'O'):
  53                     parity = val[-2]
  54                     stopbits = int(val[-1])
  55                     val = val[:-2]
  56                 speed = int(val)
  57             elif switch == '-t':
  58                 typeflag = True
  59                 rawmode = False
  60             elif switch == '-D':
  61                 debuglevel = BASELEVEL + int(val)
  62             elif switch == '-h':
  63                 sys.stderr.write("usage: gpscat [-s speed] serial-port\n")
  64                 raise SystemExit, 0
  65
  66         if "rfcomm" in arguments[0]:     # Bluetooth special case
  67             s = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM, socket.BTPROTO_RFCOMM)
  68             s.connect((arguments[0], 1))
  69             tty = s.fileno()
  70         else:                            # Ordinary device
  71             tty = os.open(arguments[0], os.O_RDWR)
  72
  73         if speed != None:
  74             (iflag, oflag, cflag, lflag, ispeed, ospeed, cc) = termios.tcgetattr(tty)
  75             try:
  76                 ispeed = ospeed = eval("termios.B%d" % speed)
  77             except AttributeError:
  78                 sys.stderr.write("gpscat: unknown baud rate %d\n" % speed)
  79                 raise SystemExit, 1
  80             if stopbits:
  81                 cflag &= ~termios.CSIZE
  82                 cflag |= (termios.CS8, termios.CS7)[stopbits-1]
  83             if parity:
  84                 if parity == 'N':
  85                     iflag &= ~termios.PARENB
  86                     iflag &= ~termios.INPCK
  87                 elif parity == 'O':
  88                     iflag |= termios.INPCK
  89                     cflag |= termios.PARENB
  90                     cflag |= termios.PARODD
  91                 elif parity == 'E':
  92                     iflag |= termios.INPCK
  93                     cflag |= termios.PARENB
  94                     cflag &= ~termios.PARODD
  95             termios.tcsetattr(tty, termios.TCSANOW,
  96                          [iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
  97
  98         poller = select.poll()
  99         poller.register(tty, select.POLLIN)
 100
 101         buf = ""
 102         if not rawmode:
 103             getter = sniffer.new()
 104             sniffer.register_report(reporter)
 105         seqno = 0
 106         while True:
 107             (fd, event) = poller.poll()[0]
 108             if fd == tty and event == select.POLLIN:
 109                 if rawmode:
 110                     buf += os.read(tty, NMEA_MAX)
 111                     sys.stdout.write(hexdump(buf))
 112                     buf = ""
 113                 else:
 114                     (length, ptype, packet) = getter.get(tty)
 115                     seqno += 1
 116                     if length == 0:
 117                         break
 118                     if typeflag:
 119                         sys.stdout.write(`ptype` + " (" + `length` + "): " + hexdump(packet))
 120                         sys.stdout.write("\n")
 121                     else:
 122                         sys.stdout.write(hexdump(packet) + "\n")
 123     except KeyboardInterrupt:
 124         if rawmode:
 125             sys.stdout.write("\n")
 126         raise SystemExit, 0
 127
 128 # Local variables:
 129 # mode: python
 130 # end:
 131
 132