transport: print reader device/number on init

When we initialize the reader, we currently tell only which type of
interface we are using, but we do not print the reader number or the
device path.

Let's extend the messages so that the path is printed. To prevent
problems with integration-tests, let's also add an environment variable
that we can use to detect when pySim runs inside a integration-test.

Related: OS#6210
Change-Id: Ibe296d51885b1ef5f9c9ecaf1d28da52014dcc4b

pySim/transport/modem_atcmd.py

@@ -21,6 +21,7 @@ import serial
 import time
 import re
 import argparse
+import os
 from typing import Optional
 
 from pySim.utils import Hexstr, ResTuple
@@ -36,7 +37,10 @@ class ModemATCommandLink(LinkBase):
 
     def __init__(self, device: str = '/dev/ttyUSB0', baudrate: int = 115200, **kwargs):
         super().__init__(**kwargs)
-        print("Using modem for Generic SIM Access (3GPP TS 27.007)")
+        if os.environ.get('PYSIM_INTEGRATION_TEST') == "1":
+            print("Using modem for Generic SIM Access (3GPP TS 27.007)")
+        else:
+            print("Using modem for Generic SIM Access (3GPP TS 27.007) at port %s" % device)
         self._sl = serial.Serial(device, baudrate, timeout=5)
         self._echo = False		# this will be auto-detected by _check_echo()
         self._device = device