Sensing...

I came across a new problem, at least for me, in ubuntu 14.04, while trying to mount the NTFS drives. It was just saying that I did not turned off windows system properly and therefore the filesystem is corrupt. I could mount the file system in the readonly mode. sudo mount -t "ntfs" -ro "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda3" "/media/bidur/d" For that, I have to create a new directory beforehand i.e. "/media/bidur/d". Just now, I came across a way to deal with the problem by using ntfsfix commad: sudo ntfsfix /dev/sda3

Pipes can be used in python using the popen command. os.popen(command[, mode[, bufferSize]]). The default mode is read which can also be explicitly indicated by "r" as shown in the example below. The parameter bufferSize can be 0 (no buffering), 1 (line buffering), negative(system default buffering) and positive values greater than 1 (number defines the buffer size to be used). #Open a pipe to or from command import os # shell command to show all the files in current directory with ".py" in the file name shellCommand = ' ls | grep .py' pipe = os.popen(shellCommand,"r") while True: # read each output line line = pipe.readline() if not line: break print 'outputLine: ' print line

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

Keyhole Markup Language (KML) is a xml standard which can be used to define what and how to present geographic data in Google Earth and Google Maps. Useful examples to start can be browsed via https://developers.google.com/kml/documentation/kml_tut . I have to display KML data in googleearth. And the KML file has to be loaded dynamically and the updates in the kml file should be shown in the googleearth on the fly. For this we have to Create a Network Link. Goto Add -> Network Link Then specify the details as shown in the figure. To specify the frequency of updating the data, go to Refresh tab. The code for dynamicKML.kml is as follows: junk.kml onInterval 5 Note that, we are using a local file junk.kml   ( junk.kml and dynamciKML.kml reside in the same directory) to define the content to be displayed in the google earth interface. This can even be a remote file in which case we have t...

The  socket.gethostname() function is supposed to give the IP address of the machine but it may not give the real IP address but gives 127.0.0.1 . Even it is said that removing 127.0.0.1 from the /etc/hosts file (in ubuntu) can give the real IP but it could not help in my case. import socket nodeName = socket.gethostname() info = socket.getaddrinfo(nodeName, None, 0, socket.SOCK_STREAM) print [x[4][0] for x in info]   # prints 127.0.0.1 I came through another way which can print the real IP as well: import commands NodeIPS = commands.getoutput("/sbin/ifconfig | grep -i \"inet\" | grep -iv \"inet6\" | " +                          "awk {'print $2'} | sed -ne 's/addr\:/ /p'") print NodeIPS  # prints 127.0.0.1 and realIP(eg. 202.145.12.22) Note: code worked for ubuntu 12.04 and python 2.7 Sometimes its handy to have the IP address as list items. The following code does the work. impo...

In ubuntu 12.04, While browsing files in nautilus, if we want to open file with unlisted applications, for e.g. open a file with idle(but idle is not listed in the list of open with ). Enter the following command in the terminal: gksudo gedit /usr/share/applications/idle.desktop Then remove the line: Exec=/usr/bin/idle -n Replace it with: Exec=idle %U Now we can see idle listed in the list of open with applications. To set it as default application to open a file. Go to the file properites, select idle and click set as default.