392 lines
15 KiB
Python
392 lines
15 KiB
Python
#!/usr/bin/env python
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#module for serial IO for POSIX compatible systems, like Linux
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#see __init__.py
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#
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#(C) 2001-2002 Chris Liechti <cliechti@gmx.net>
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# this is distributed under a free software license, see license.txt
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#
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#parts based on code from Grant B. Edwards <grante@visi.com>:
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# ftp://ftp.visi.com/users/grante/python/PosixSerial.py
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# references: http://www.easysw.com/~mike/serial/serial.html
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import sys, os, fcntl, termios, struct, string, select
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import serialutil
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VERSION = string.split("$Revision: 1.1 $")[1] #extract CVS version
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PARITY_NONE, PARITY_EVEN, PARITY_ODD = range(3)
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STOPBITS_ONE, STOPBITS_TWO = (1, 2)
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FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS = (5,6,7,8)
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#Do check the Python version as some constants have moved.
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if (sys.hexversion < 0x020100f0):
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import TERMIOS
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else:
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TERMIOS = termios
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if (sys.hexversion < 0x020200f0):
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import FCNTL
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else:
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FCNTL = fcntl
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#try to detect the os so that a device can be selected...
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plat = string.lower(sys.platform)
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if plat[:5] == 'linux': #Linux (confirmed)
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def device(port):
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return '/dev/ttyS%d' % port
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elif plat == 'cygwin': #cywin/win32 (confirmed)
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def device(port):
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return '/dev/com%d' % (port + 1)
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elif plat == 'openbsd3': #BSD (confirmed)
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def device(port):
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return '/dev/ttyp%d' % port
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elif plat[:3] == 'bsd' or \
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plat[:6] == 'netbsd' or \
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plat[:7] == 'freebsd' or \
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plat[:7] == 'openbsd' or \
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plat[:6] == 'darwin': #BSD (confirmed for freebsd4: cuaa%d)
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def device(port):
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return '/dev/cuaa%d' % port
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elif plat[:4] == 'irix': #IRIX (not tested)
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def device(port):
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return '/dev/ttyf%d' % port
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elif plat[:2] == 'hp': #HP-UX (not tested)
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def device(port):
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return '/dev/tty%dp0' % (port+1)
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elif plat[:5] == 'sunos': #Solaris/SunOS (confirmed)
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def device(port):
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return '/dev/tty%c' % (ord('a')+port)
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elif plat[:3] == 'dgux': #Digital UNIX (not tested)
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def device(port):
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return '/dev/tty0%d' % (port+1)
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else:
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#platform detection has failed...
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info = "sys.platform = %r\nos.name = %r\nserialposix.py version = %s" % (sys.platform, os.name, VERSION)
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print """send this information to the author of this module:
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%s
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also add the device name of the serial port and where the
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counting starts for the first serial port.
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e.g. 'first serial port: /dev/ttyS0'
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and with a bit luck you can get this module running...
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"""
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raise Exception, "this module does not run on this platform, sorry."
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#whats up with "aix", "beos", "sco", ....
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#they should work, just need to know the device names.
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# construct dictionaries for baud rate lookups
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baudEnumToInt = {}
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baudIntToEnum = {}
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for rate in (0,50,75,110,134,150,200,300,600,1200,1800,2400,4800,9600,
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19200,38400,57600,115200,230400,460800,500000,576000,921600,
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1000000,1152000,1500000,2000000,2500000,3000000,3500000,4000000
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):
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try:
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i = eval('TERMIOS.B'+str(rate))
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baudEnumToInt[i]=rate
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baudIntToEnum[rate] = i
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except:
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pass
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#load some constants for later use.
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#try to use values from TERMIOS, use defaults from linux otherwise
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TIOCMGET = hasattr(TERMIOS, 'TIOCMGET') and TERMIOS.TIOCMGET or 0x5415
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TIOCMBIS = hasattr(TERMIOS, 'TIOCMBIS') and TERMIOS.TIOCMBIS or 0x5416
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TIOCMBIC = hasattr(TERMIOS, 'TIOCMBIC') and TERMIOS.TIOCMBIC or 0x5417
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TIOCMSET = hasattr(TERMIOS, 'TIOCMSET') and TERMIOS.TIOCMSET or 0x5418
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#TIOCM_LE = hasattr(TERMIOS, 'TIOCM_LE') and TERMIOS.TIOCM_LE or 0x001
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TIOCM_DTR = hasattr(TERMIOS, 'TIOCM_DTR') and TERMIOS.TIOCM_DTR or 0x002
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TIOCM_RTS = hasattr(TERMIOS, 'TIOCM_RTS') and TERMIOS.TIOCM_RTS or 0x004
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#TIOCM_ST = hasattr(TERMIOS, 'TIOCM_ST') and TERMIOS.TIOCM_ST or 0x008
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#TIOCM_SR = hasattr(TERMIOS, 'TIOCM_SR') and TERMIOS.TIOCM_SR or 0x010
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TIOCM_CTS = hasattr(TERMIOS, 'TIOCM_CTS') and TERMIOS.TIOCM_CTS or 0x020
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TIOCM_CAR = hasattr(TERMIOS, 'TIOCM_CAR') and TERMIOS.TIOCM_CAR or 0x040
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TIOCM_RNG = hasattr(TERMIOS, 'TIOCM_RNG') and TERMIOS.TIOCM_RNG or 0x080
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TIOCM_DSR = hasattr(TERMIOS, 'TIOCM_DSR') and TERMIOS.TIOCM_DSR or 0x100
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TIOCM_CD = hasattr(TERMIOS, 'TIOCM_CD') and TERMIOS.TIOCM_CD or TIOCM_CAR
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TIOCM_RI = hasattr(TERMIOS, 'TIOCM_RI') and TERMIOS.TIOCM_RI or TIOCM_RNG
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#TIOCM_OUT1 = hasattr(TERMIOS, 'TIOCM_OUT1') and TERMIOS.TIOCM_OUT1 or 0x2000
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#TIOCM_OUT2 = hasattr(TERMIOS, 'TIOCM_OUT2') and TERMIOS.TIOCM_OUT2 or 0x4000
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TIOCINQ = hasattr(TERMIOS, 'FIONREAD') and TERMIOS.FIONREAD or 0x541B
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TIOCM_zero_str = struct.pack('I', 0)
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TIOCM_RTS_str = struct.pack('I', TIOCM_RTS)
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TIOCM_DTR_str = struct.pack('I', TIOCM_DTR)
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portNotOpenError = ValueError('port not open')
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class Serial(serialutil.FileLike):
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def __init__(self,
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port, #number of device, numbering starts at
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#zero. if everything fails, the user
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#can specify a device string, note
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#that this isn't portable anymore
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baudrate=9600, #baudrate
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bytesize=EIGHTBITS, #number of databits
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parity=PARITY_NONE, #enable parity checking
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stopbits=STOPBITS_ONE, #number of stopbits
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timeout=None, #set a timeout value, None for waiting forever
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xonxoff=0, #enable software flow control
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rtscts=0, #enable RTS/CTS flow control
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):
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"""init comm port"""
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self.fd = None
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self.timeout = timeout
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vmin = vtime = 0 #timeout is done via select
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#open
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if type(port) == type(''): #strings are taken directly
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self.portstr = port
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else:
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self.portstr = device(port) #numbers are transformed to a os dependant string
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try:
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self.fd = os.open(self.portstr, os.O_RDWR|os.O_NOCTTY|os.O_NONBLOCK)
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except Exception, msg:
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self.fd = None
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raise serialutil.SerialException, "could not open port: %s" % msg
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fcntl.fcntl(self.fd, FCNTL.F_SETFL, 0) #set blocking
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try:
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self.__tcgetattr() #read current settings
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except termios.error, msg: #if a port is nonexistent but has a /dev file, it'll fail here
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raise serialutil.SerialException, "could not open port: %s" % msg
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#set up raw mode / no echo / binary
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self.cflag = self.cflag | (TERMIOS.CLOCAL|TERMIOS.CREAD)
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self.lflag = self.lflag & ~(TERMIOS.ICANON|TERMIOS.ECHO|TERMIOS.ECHOE|TERMIOS.ECHOK|TERMIOS.ECHONL|
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TERMIOS.ECHOCTL|TERMIOS.ECHOKE|TERMIOS.ISIG|TERMIOS.IEXTEN) #|TERMIOS.ECHOPRT
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self.oflag = self.oflag & ~(TERMIOS.OPOST)
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if hasattr(TERMIOS, 'IUCLC'):
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self.iflag = self.iflag & ~(TERMIOS.INLCR|TERMIOS.IGNCR|TERMIOS.ICRNL|TERMIOS.IUCLC|TERMIOS.IGNBRK)
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else:
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self.iflag = self.iflag & ~(TERMIOS.INLCR|TERMIOS.IGNCR|TERMIOS.ICRNL|TERMIOS.IGNBRK)
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#setup baudrate
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try:
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self.ispeed = self.ospeed = baudIntToEnum[baudrate]
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except:
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raise ValueError,'invalid baud rate: %s' % baudrate
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#setup char len
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self.cflag = self.cflag & ~TERMIOS.CSIZE
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if bytesize == 8:
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self.cflag = self.cflag | TERMIOS.CS8
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elif bytesize == 7:
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self.cflag = self.cflag | TERMIOS.CS7
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elif bytesize == 6:
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self.cflag = self.cflag | TERMIOS.CS6
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elif bytesize == 5:
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self.cflag = self.cflag | TERMIOS.CS5
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else:
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raise ValueError,'invalid char len: '+str(clen)
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#setup stopbits
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if stopbits == STOPBITS_ONE:
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self.cflag = self.cflag & ~(TERMIOS.CSTOPB)
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elif stopbits == STOPBITS_TWO:
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self.cflag = self.cflag | (TERMIOS.CSTOPB)
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else:
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raise ValueError,'invalid stopit specification:'+str(stopbits)
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#setup parity
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self.iflag = self.iflag & ~(TERMIOS.INPCK|TERMIOS.ISTRIP)
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if parity == PARITY_NONE:
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self.cflag = self.cflag & ~(TERMIOS.PARENB|TERMIOS.PARODD)
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elif parity == PARITY_EVEN:
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self.cflag = self.cflag & ~(TERMIOS.PARODD)
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self.cflag = self.cflag | (TERMIOS.PARENB)
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elif parity == PARITY_ODD:
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self.cflag = self.cflag | (TERMIOS.PARENB|TERMIOS.PARODD)
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else:
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raise ValueError,'invalid parity: '+str(par)
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#setup flow control
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#xonxoff
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if hasattr(TERMIOS, 'IXANY'):
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if xonxoff:
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self.iflag = self.iflag | (TERMIOS.IXON|TERMIOS.IXOFF|TERMIOS.IXANY)
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else:
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self.iflag = self.iflag & ~(TERMIOS.IXON|TERMIOS.IXOFF|TERMIOS.IXANY)
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else:
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if xonxoff:
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self.iflag = self.iflag | (TERMIOS.IXON|TERMIOS.IXOFF)
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else:
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self.iflag = self.iflag & ~(TERMIOS.IXON|TERMIOS.IXOFF)
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#rtscts
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if hasattr(TERMIOS, 'CRTSCTS'):
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if rtscts:
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self.cflag = self.cflag | (TERMIOS.CRTSCTS)
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else:
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self.cflag = self.cflag & ~(TERMIOS.CRTSCTS)
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elif hasattr(TERMIOS, 'CNEW_RTSCTS'): #try it with alternate constant name
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if rtscts:
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self.cflag = self.cflag | (TERMIOS.CNEW_RTSCTS)
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else:
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self.cflag = self.cflag & ~(TERMIOS.CNEW_RTSCTS)
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#XXX should there be a warning if setting up rtscts (and xonxoff etc) fails??
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#buffer
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#vmin "minimal number of characters to be read. = for non blocking"
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if vmin<0 or vmin>255:
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raise ValueError,'invalid vmin: '+str(vmin)
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self.cc[TERMIOS.VMIN] = vmin
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#vtime
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if vtime<0 or vtime>255:
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raise ValueError,'invalid vtime: '+str(vtime)
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self.cc[TERMIOS.VTIME] = vtime
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#activate settings
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self.__tcsetattr()
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def __tcsetattr(self):
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"""internal function to set port attributes"""
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termios.tcsetattr(self.fd, TERMIOS.TCSANOW, [self.iflag,self.oflag,self.cflag,self.lflag,self.ispeed,self.ospeed,self.cc])
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def __tcgetattr(self):
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"""internal function to get port attributes"""
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self.iflag,self.oflag,self.cflag,self.lflag,self.ispeed,self.ospeed,self.cc = termios.tcgetattr(self.fd)
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def close(self):
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"""close port"""
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if self.fd:
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os.close(self.fd)
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self.fd = None
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def setBaudrate(self, baudrate):
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"""change baudrate after port is open"""
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if not self.fd: raise portNotOpenError
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self.__tcgetattr() #read current settings
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#setup baudrate
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try:
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self.ispeed = self.ospeed = baudIntToEnum[baudrate]
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except:
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raise ValueError,'invalid baud rate: %s' % baudrate
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self.__tcsetattr()
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def inWaiting(self):
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"""how many character are in the input queue"""
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#~ s = fcntl.ioctl(self.fd, TERMIOS.FIONREAD, TIOCM_zero_str)
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s = fcntl.ioctl(self.fd, TIOCINQ, TIOCM_zero_str)
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return struct.unpack('I',s)[0]
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def write(self, data):
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"""write a string to the port"""
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if not self.fd: raise portNotOpenError
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t = len(data)
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d = data
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while t>0:
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n = os.write(self.fd, d)
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d = d[n:]
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t = t - n
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def read(self, size=1):
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"""read a number of bytes from the port.
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the default is one (unlike files)"""
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if not self.fd: raise portNotOpenError
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read = ''
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inp = None
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if size > 0:
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while len(read) < size:
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#print "\tread(): size",size, "have", len(read) #debug
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ready,_,_ = select.select([self.fd],[],[], self.timeout)
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if not ready:
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break #timeout
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buf = os.read(self.fd, size-len(read))
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read = read + buf
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if self.timeout >= 0 and not buf:
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break #early abort on timeout
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return read
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def flushInput(self):
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"""clear input queue"""
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if not self.fd:
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raise portNotOpenError
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termios.tcflush(self.fd, TERMIOS.TCIFLUSH)
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def flushOutput(self):
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"""flush output"""
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if not self.fd:
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raise portNotOpenError
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termios.tcflush(self.fd, TERMIOS.TCOFLUSH)
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def sendBreak(self):
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"""send break signal"""
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if not self.fd:
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raise portNotOpenError
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termios.tcsendbreak(self.fd, 0)
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def drainOutput(self):
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"""internal - not portable!"""
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if not self.fd: raise portNotOpenError
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termios.tcdrain(self.fd)
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def nonblocking(self):
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"""internal - not portable!"""
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if not self.fd:
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raise portNotOpenError
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fcntl.fcntl(self.fd, FCNTL.F_SETFL, FCNTL.O_NONBLOCK)
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def getDSR(self):
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"""read terminal status line"""
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if not self.fd: raise portNotOpenError
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s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
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return struct.unpack('I',s)[0] & TIOCM_DSR
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def getCD(self):
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"""read terminal status line"""
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if not self.fd: raise portNotOpenError
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s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
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return struct.unpack('I',s)[0] & TIOCM_CD
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def getRI(self):
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"""read terminal status line"""
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if not self.fd: raise portNotOpenError
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s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
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return struct.unpack('I',s)[0] & TIOCM_RI
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def getCTS(self):
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"""read terminal status line"""
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if not self.fd: raise portNotOpenError
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s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
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return struct.unpack('I',s)[0] & TIOCM_CTS
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def setDTR(self,on=1):
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"""set terminal status line"""
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if not self.fd: raise portNotOpenError
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if on:
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fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_DTR_str)
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else:
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fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_DTR_str)
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def setRTS(self,on=1):
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"""set terminal status line"""
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if not self.fd: raise portNotOpenError
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if on:
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fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_RTS_str)
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else:
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fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_RTS_str)
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if __name__ == '__main__':
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s = Serial(0,
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baudrate=19200, #baudrate
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bytesize=EIGHTBITS, #number of databits
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parity=PARITY_EVEN, #enable parity checking
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stopbits=STOPBITS_ONE, #number of stopbits
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timeout=3, #set a timeout value, None for waiting forever
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xonxoff=0, #enable software flow control
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rtscts=0, #enable RTS/CTS flow control
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)
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s.setRTS(1)
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s.setDTR(1)
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s.flushInput()
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s.flushOutput()
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s.write('hello')
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print repr(s.read(5))
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print s.inWaiting()
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del s
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