Sensing...

The following program finds out the hop count of the nodes in a connected network. Hop Count means the number of point to point connections in a graph of network. For example, in the graph shown below the hop count from node a to node b is one, node b to node c is two, etc. This program assumes the graph given above. usage : getHopCount(dictNeigh, node1,node2) Where:   dictNeigh : dictionary of list of neighbor of each node in the network node1 and node2 are the nodes for which hop count is calculated by the program Exception: if the nodes are not connected then it returns Zero import copy dictNeigh = dict() # dictNeigh defines the neighbors dictNeigh['a'] = ['b','c','d'] # neighbors of 'a' dictNeigh['b'] = ['a']# neighbors of 'b' dictNeigh['c'] = ['a','d'] dictNeigh['d'] = ['a','c','e'] dictNeigh['e'] = ['d','f'] dictN...

Sometimes the port assigned to apache2 may be used by some other services. In such cases, if we try to live apache2 server then it fails.  The following message is shown in ubuntu 10.04 in my case: Starting web server apache2                                                   apache2: Could not reliably determine the server's fully qualified domain name, using 0.0.0.3 for ServerName (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down Unable to open logs Here is one of the ways to overcome this problem: 1. see who is using the port 80 : sudo lsof -i :80 2. get the pid of the services in 1. E.g.: 1577 3. kill all the services in 2. : sudo kill 1577 4. restart apache2: sudo /etc/init.d/apache2 restart