TOPIC: COMMAND SHELLS
Resolving Windows Update Error 0x80244019 on Windows 10
21st August 2015In Windows 10, the preferred place to look if you fancy prompting an update of the system is in the Update & Security section of the Settings application. At the top is the Windows Update, and the process usually is as simple as pressing the Check for updates button. For most of the time, that has been my experience, but it stopped working on my main Windows 10 virtual machine, so I needed to resolve the problem.
Initially, going into the Advanced Options section and deselecting the tick box for Give me updates for other Microsoft products when I update Windows helped. However, it seemed a non-ideal solution, so I looked further. When it was then that I found that manually resetting a system's Windows Updates components helped others, I tried that and restarted the system.
The first part of the process was to right-click on the Start Menu button and select the Windows PowerShell (Admin) entry from the menu that appeared. This may be replaced by Command Prompt (Admin) on your system on your machine, but the next steps in the process are the same. In fact, you could include any commands you see below in a script file and execute that if you prefer. Here, I will run through each group in succession.
From either PowerShell or the Command Prompt, you need to stop the Windows Update, Cryptographic, BITS (or Background Intelligent Transfer Service) and MSI Installer services. To accomplish this, execute the following commands at a command prompt:
net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
With the services stopped, it is then possible to rename the SoftwareDistribution and Catroot2 folders so you can refresh everything to remove them. To accomplish this, execute the following pair of commands using either PowerShell or the Command Prompt:
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 Catroot2.old
Once you have the folders renamed, then you can start the Windows Update, Cryptographic, BITS and MSI Installer services by executing the following commands in either PowerShell or the Command Prompt:
net start wuauserv
net start cryptSvc
net start bits
net start msiserver
Once these have completed, you may close the PowerShell or Command Prompt window that you were using and restart the machine. Going into the Update & Security section of the Settings tool afterwards and pressing the Check for updates button now builds new versions of the folders that you renamed, and this takes a little while longer than the usual update process. Otherwise, you could let your system rebuild things in its own time. As it happens, I opted for manual intervention and all has worked well since then.
Windows commands for setting default applications for opening certain file types
18th August 2015On Friday, I was working on a system where a session is instantiated from a stored virtual machine that produces a fresh session every time, meaning that all previous changes get lost. What I have is a batch script that I run to reinstate what I need, and I encountered another task that I wanted it to do.
Part of my work involves the creation of plain text files with the extension lst and this is getting associated with SAS instead of Notepad. While you can reassign such associations using the GUI, it would be a bonus to do it via the command line too, so the assoc and ftype commands caught my interest. The first of these associates a file with a given extension with a desired file type, while the second shows the available file types together with the associated applications that open them. The assoc command also shows all the associations that are in place when it is executed with no parameters, and the ftype command does the same for file types.
Once you have picked out a file type with the ftype command, then the assoc can be used like the following:
assoc .lst=txtfile
The above associates an extension with a file type. In this, .lst files are going to get opened by Notepad because of the txtfile association. Though it did not do what I wanted on Friday due to system lockdown, it is good to know that this is possible and that even the Windows command line supports goodies like these.
Creating empty text files and changing file timestamps using Windows Command Prompt & Powershell
17th May 2013Linux and UNIX have the touch command for changing the creation dates and times for files. However, it also creates empty text files for you as well. In fact, there are times when I feel the need to do this sort of thing on Windows too and the following command accomplishes the deed when run in a Command Prompt window:
type nul > command.bat
Essentially, null output is sent to a file that is created anew, command.bat in this case. Then, you can edit it in Notepad (or whatever is your choice of text editor) and add in what you need. This will not work in PowerShell, so you need another command for that:
New-Item command.bat -type file1
This uses the New-Item command, which also can be used to create folders as well if you so desire. Then, the command becomes the following:
New-Item c:\commands -type directory1
Note that file1 in the previous example has become directory1 and there is the -force option should you need to overwrite what already exists for some reason...
That other use of the UNIX/Linux touch command can be performed from the Command Prompt too, and here is an example command:
copy /b file.txt +,,
The /b switch switches on binary behaviour for the copy command, though that appears to be the default action anyway. The + operator triggers concatenation and ,, gets around not having a defined destination because you cannot copy a file over itself. If that were possible, then there would no need for special syntax for changing the date and time for a file.
For doing the same thing with PowerShell, try the following:
(GetChildItem test.txt).LastWriteTime=Get-Date
The GetChildItem command has aliases of gci, dir and ls and the last two of these give away its essential purpose. Here, it is used to pick out the test.txt file so that its timestamp can be replaced with the current date and time returned by the Get-Date command. The syntax looks a little more complex, even if it achieves the same end. Somehow, that touch command is easier to explain. Are Linux and UNIX that complicated, after all?
Checking existence of files and directories on UNIX using shell scripting
23rd April 2007Having had a UNIX shell script attempt to copy a non-existent file, I decided to take another look for ways to test the existence of a file. For directory existence checking, I was testing for the return code from the cd command, and I suppose that the ls command might help for files. However, I did find a better way:
if [ -f $filename ]
then
echo "This filename [$filename] exists"
elif [ -d $dirname ]
then
echo "This dirname [$dirname] exists"
else
echo "Neither [$dirname] or [$filename] exist"
fiThe -d and -f flags within the evaluation expressions test for the existence of directories and files, respectively. One gotcha is that those spaces within the brackets are important too, but it is a very way of doing what I wanted.