Posts Tagged ‘commandline’
Changing the port number of SSH daemon is a quick way of reducing the number of SSH brute force attacks your server might face (check the file /var/log/auth.log to see if there are many failed SSH login attempts). Just to be on the safe side, create a backup copy of the SSH daemon config file. [...]
Good article on Tuxradar with some clever command line hacks: Command line tricks for smart geeks
Here’s how to find the version of your CentOS system from the command line: more /etc/redhat-release
This post is about how to change the resolution (i.e. font size) of virtual terminals or “tty” in Linux. Virtual terminal is the basic command line interface which you see when you press <Ctrl><Alt><F1> (note: to get back to your existing Gnome or KDE session press <Alt><F7>). This is different from the Terminal emulator, such [...]
Sometimes it is necessary to split a large file into several smaller ones, for example so that they fit on a CD or USB disk or can be attached to email. It’s very easy to do this from command line. Suppose you have a file of 500 MiB called “large_file” and to split it into [...]
Nautilus and Thunar sometimes refuse to mount NTFS disk (e.g. a USB hard drive) when it was previously not unmounted cleanly from Windows. It is still possible to mount it from terminal shell by using the following command: sudo mount -t ntfs-3g -o force /dev/sdc1 /media/myntfsdisk Where /dev/sdc1 is the device you want to mount [...]
To check for installed packages from the command line, use the dpkg command with the –get-selections option. This returns all packages installed on your system (most likely a lot!). So it is best to use grep to narrow down the search results. For example, the following command lists all packages with “fire” in the package [...]
There is a simple tutorial on Ars Technica’s Open Ended site with several useful examples of the grep command. Further examples can be found in the comments section.
Medical images, e.g. X-Rays, are commonly stored in the DICOM format. By default you won’t be able to open these in Ubuntu, but there is actually a package in the repositories which lets you convert DICOM image files to more common formats, e.g. JPEG, PNG or bitmap. sudo apt-get install dcmtk dcmj2pnm +oj img00000 img00000.jpg [...]
Sometimes you may want to log in with a different user account in Terminal without logging out from your X session or switching to an unused virtual console. There are two different approaches to do this in Ubuntu: interestingly, it is possible without even knowing the other user’s password. Approach 1: if you know the [...]