test read seraile iniziale

IOB-PI/ReadSerialePython_2test/unix.py

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+import fcntl
+import os
+
+
+#---------------------------------------------------------------
+# meccanismo di file lock per evitare multiple instances
+# The function will try to lock the file specified , if it success, return True, else return False.
+# The nice thing is that the lock will be dropped when the program terminates.
+# >>>Use : 
+# if not lockFile(".lock.pod"):
+#        sys.exit(0)
+
+def lockFile ( lockfile ) :
+
+    fd = os.open ( lockfile , os.O_CREAT | os.O_TRUNC | os.O_WRONLY )
+    try:
+        # Request exclusive (EX) non-blocking (NB) advisory lock.
+        fcntl.lockf ( fd , fcntl.LOCK_EX | fcntl.LOCK_NB )
+    except IOError:
+        return False
+
+    return True
+
+if not lockFile ( ".lockfile" ) :
+    print '\n noi non siamo soli ...\n'
+    logga ( "LOCK: Piu istanze aperte")
+    sys.exit ( 0 )
+
+#- print '\n running alone ...\n'
+
+