c# barcode zebra printer Profiles, prompts, and colors: customizing the shell in VB.NET

Make ECC200 in VB.NET Profiles, prompts, and colors: customizing the shell

PowerShell itself; on most systems, that s in C:\Windows\System32\WindowsPowerShell\v1.0 (for the 64-bit version of the shell on a 64-bit system). $home is another built-in variable that points to the current user s profile folder (such as C:\Users\Administrator). I ve used Documents to refer to the Documents folder, but on some versions of Windows it will be My Documents. I ve written no matter which host they re using, but that technically isn t true. It s true of hosting applications (the console and the ISE) written by Microsoft, but there s no way to force the authors of non-Microsoft hosting applications to follow these rules.

Because I want the same shell extensions to load whether I m using the console host or the ISE, I chose to customize $home\Documents\WindowsPowerShell\profile.ps1, because that profile is run for both of the Microsoft-supplied hosting applications.

Even if all you put in them is a simple message, such as Write "It Worked", this is a good way to see the different files in action. Remember that you have to close the shell (or ISE) and re-open it to see the profile scripts run. Keep in mind that profile scripts are scripts and are subject to your shell s current execution policy. If your execution policy is Restricted, your profile won t run; if your policy is AllSigned, your profile must be signed. 14 discussed the execution policy and script signing.

The PowerShell prompt the PS C:\> that you ve seen through much of this book is generated by a built-in function called Prompt. If you want to customize the prompt, you can simply replace that function. Defining a new Prompt function is something that can be done in a profile script, so that your change takes effect each time you open the shell. Here s the default prompt:

function prompt { $(if (test-path variable:/PSDebugContext) { '[DBG]: ' } else { '' }) + 'PS ' + $(Get-Location) ` + $(if ($nestedpromptlevel -ge 1) { '>>' }) + '> ' }

This prompt first tests to see if the $DebugContext variable is defined in the shell s VARIABLE: drive. If it is, this function adds [DBG]: to the start of the prompt. Otherwise, the prompt is defined as PS along with the current location, which is returned by

the Get-Location cmdlet. If the shell is in a nested prompt, as defined by the built-in $nestedpromptlevel variable, the prompt will have >> added to it. This next listing is an alternative prompt function. You could enter this directly into any profile script to make it the standard prompt for your shell sessions.

function prompt { $time = (Get-Date).ToShortTimeString() "$time [$env:COMPUTERNAME]:> " }

This alternative prompt displays the current time, followed by the current computer name (which will be contained within square brackets). Note that this leverages PowerShell s special behavior with double quotation marks, in which the shell will replace variables (like $time) with their contents.

In previous chapters, I ve mentioned how stressed-out I can get when a long series of error messages scrolls by in the shell. I always struggled in English class when I was a kid, and seeing all that red text reminds me of the essays I d get back from Ms. Hansen, all marked up with a red pen. Yuck. Fortunately, PowerShell gives you the ability to modify most of the default colors it uses. The default text foreground and background colors can be modified by clicking on the control box in the upper-left corner of PowerShell s window. From there, select Properties, and then select the Colors tab, which is shown in figure 24.1. Figure 24.1 Configuring the default shell Modifying the colors of errors, screen colors warnings, and other messages is a bit trickier and requires you to run a command. But you could put this command into your profile, so that it executes each time you open the shell. Here s how to change the error message foreground color to green, which I find a lot more soothing:

(Get-Host).PrivateData.ErrorForegroundColor = "green"