Adventures & experiences in contemporary technology
One thing that is very handy for shell scripting is to have automated entry of passwords for logging into other servers. This can involve using plain text files, which is not always ideal so it was good to find an alternative. The first step is to use the keygen tool that comes with SSH. The command is given below and the -t switch specifies the type of key to be made, RSA in this case. There is the option to add a passphrase but I decided against this for sake of convenience and you do need to assess your security needs before embarking on such a course of action.
ssh-keygen -t rsa
The next step is to use the ssh-copy-id command to generate the keys for a set of login credentials. For this, it is better to use a user account with restricted access to keep as much server security as you can. Otherwise, the process is as simple as executing a command like the following and entering the password at the prompt for doing so.
ssh-copy-id [user ID]@[server address]
Getting this set up has been useful for running a file upload script to keep a web server synchronised and it is better to have the credentials encrypted rather than kept in a plain text file.
Having made plenty of use of grep on the Linux/UNIX command and findstr on the legacy Windows command line, I wondered if PowerShell could be used to search the contents of files for a text string. Usefully, this turns out to be the case but I found that the native functionality does not use what I have used before. The form of the command is given below:
Select-String -Path <filename search expression> -Pattern "<search expression>" > <output file>
While you can have the output appear on screen, it always seems easier to send it to a file for subsequent and that is what I am doing above. The input to the -Path switch can be a filename or a wildcard expression while that to the -Pattern can be a text string enclosed in quotes or a regular expression. It works well once you know what to do so here is an example:
Select-String -Path *.sas -Pattern "proc report" > c:\temp\search.txt
The search.txt file then includes both the file information and the text that has been found for sake of checking that you have what you want. What you do next is up to you.
Recently, I managed to use 10AppsManager to remove most of the in-built apps from a Windows 10 virtual machine that I have for testing development versions in case anything ugly were to appear in a production update. Curiosity is my excuse for letting the tool do what it did and some could do with restoration. Out of the lot, Windows Store is the main one that I have sorted so far.
The first step of the process was to start up PowerShell in administrator mode. On my system, this is as simple as clicking on the relevant item in the menu popped up by right clicking on the Start Menu button and clicking on the Yes button in the dialogue box that appears afterwards. In your case, it might be a case of right clicking on the appropriate Start Menu programs entry, selecting the administrator option and going from there.
With this PowerShell session open, the first command to issue is the following:
Get-Appxpackage -Allusers > c:\temp\appxpackage.txt
This creates a listing of Windows app information and pops it into a text file in your choice of directory. Opening the text file in Notepad allows you to search it more easily and there is an entry for Windows Store:
Name : Microsoft.WindowsStore
Publisher : CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
Architecture : X64
ResourceId :
Version : 11607.1001.32.0
PackageFullName : Microsoft.WindowsStore_11607.1001.32.0_x64__8wekyb3d8bbwe
InstallLocation : C:\Program Files\WindowsApps\Microsoft.WindowsStore_11607.1001.32.0_x64__8wekyb3d8bbwe
IsFramework : False
PackageFamilyName : Microsoft.WindowsStore_8wekyb3d8bbwe
PublisherId : 8wekyb3d8bbwe
PackageUserInformation : {S-1-5-21-3224249330-198124288-2558179248-1001
IsResourcePackage : False
IsBundle : False
IsDevelopmentMode : False
Dependencies : {Microsoft.VCLibs.140.00_14.0.24123.0_x64__8wekyb3d8bbwe,
Microsoft.NET.Native.Framework.1.3_1.3.24201.0_x64__8wekyb3d8bbwe,
Microsoft.NET.Native.Runtime.1.3_1.3.23901.0_x64__8wekyb3d8bbwe,
Microsoft.WindowsStore_11607.1001.32.0_neutral_split.scale-100_8wekyb3d8bbwe}
Using the information from the InstallLocation field, the following command can be built and executed (here, it has gone over several lines so you need to get your version onto a single one):
Add-AppxPackage -register “C:\Program Files\WindowsApps\Microsoft.WindowsStore_11607.1001.32.0_x64__8wekyb3d8bbwe\AppxManifest.xml” -DisableDevelopmentMode
Once the above has completed, the app was installed and ready to use again. As the mood took me, I installed other apps from the Windows Store as I saw fit.
On Friday, I was working on a system where a session is instantiated from a stored virtual machine that produces a fresh session every time so 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 nice 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 show 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 the 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.