TRY IT NOW You ll definitely want to run this command yourself to see the in Visual Basic .NET

Printer Data Matrix 2d barcode in Visual Basic .NET TRY IT NOW You ll definitely want to run this command yourself to see the

TRY IT NOW You ll definitely want to run this command yourself to see the
Making DataMatrix In Visual Basic .NET
Using Barcode creator for Visual Studio .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
ECC200 Reader In Visual Basic .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
colorful results.
Generate Code-128 In VB.NET
Using Barcode encoder for .NET Control to generate, create ANSI/AIM Code 128 image in .NET applications.
www.OnBarcode.com
Barcode Printer In Visual Basic .NET
Using Barcode creation for VS .NET Control to generate, create Barcode image in VS .NET applications.
www.OnBarcode.com
PS C:\> write-host "COLORFUL!" -fore yellow -back magenta COLORFUL!
Make USS Code 39 In VB.NET
Using Barcode generator for VS .NET Control to generate, create Code 3 of 9 image in .NET applications.
www.OnBarcode.com
GTIN - 128 Drawer In VB.NET
Using Barcode creation for .NET Control to generate, create UCC-128 image in .NET applications.
www.OnBarcode.com
Write-Host should usually be used only when you need to display a specific message,
Generate Linear In Visual Basic .NET
Using Barcode printer for .NET Control to generate, create 1D image in VS .NET applications.
www.OnBarcode.com
EAN - 14 Generation In VB.NET
Using Barcode creation for .NET framework Control to generate, create EAN - 14 image in .NET applications.
www.OnBarcode.com
perhaps using color to draw attention to it. This isn t the appropriate way to produce normal output from a script or command. For example, you should never use Write-Host to manually format a table there are better ways to produce the output, using techniques that enable PowerShell itself
Data Matrix ECC200 Printer In Visual C#.NET
Using Barcode generation for .NET framework Control to generate, create ECC200 image in .NET applications.
www.OnBarcode.com
Data Matrix 2d Barcode Maker In Java
Using Barcode encoder for Java Control to generate, create Data Matrix ECC200 image in Java applications.
www.OnBarcode.com
Figure 16.4 WriteHost bypasses the pipeline and writes directly to the hosting application s display.
Draw USS-128 In None
Using Barcode maker for Online Control to generate, create EAN 128 image in Online applications.
www.OnBarcode.com
Generating DataMatrix In Objective-C
Using Barcode drawer for iPhone Control to generate, create Data Matrix 2d barcode image in iPhone applications.
www.OnBarcode.com
Write-Output
UPC-A Reader In Visual C#
Using Barcode scanner for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Encoding Barcode In None
Using Barcode generation for Word Control to generate, create Barcode image in Word applications.
www.OnBarcode.com
to handle the formatting. We won t be covering those techniques in this chapter, but in chapter 19 you ll play with them extensively. Write-Host is also not the best way to produce error messages, warnings, debugging messages, and so on again, there are more specific ways to do those things, and you ll see those in this chapter. You probably won t use Write-Host much, if you re using the shell correctly.
EAN-13 Drawer In Java
Using Barcode printer for Android Control to generate, create GTIN - 13 image in Android applications.
www.OnBarcode.com
Barcode Encoder In Visual Studio .NET
Using Barcode creator for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
16.4 Write-Output
Create Barcode In None
Using Barcode generator for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Print Barcode In Visual Studio .NET
Using Barcode maker for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
Unlike Write-Host, Write-Output sends objects into the pipeline. Because it isn t writing directly to the display, it doesn t permit you to specify alternative colors or anything. In fact, Write-Output (or its alias, Write) isn t technically designed to display output at all. As I said, it sends objects into the pipeline it s the pipeline itself that eventually displays those objects. Figure 16.5 illustrates how this works. Refer back to chapter 8 for a quick review of how objects go from the pipeline to the screen. Here s the basic process:
EAN / UCC - 13 Generator In None
Using Barcode creator for Microsoft Word Control to generate, create EAN 13 image in Office Word applications.
www.OnBarcode.com
2D Barcode Creation In Java
Using Barcode printer for Java Control to generate, create 2D Barcode image in Java applications.
www.OnBarcode.com
Write-Output puts the String object "Hello" into the pipeline. There s nothing else in the pipeline, so "Hello" travels to the end of the pipeline, where Out-Default always sits. Out-Default passes the object to Out-Host. Out-Host asks PowerShell s formatting system to format the object. Because in this example it s a simple String, the formatting system returns the text of the
string.
Out-Host places the formatted result onto the screen.
The results are similar to what you d get using Write-Host, but the object took a very different path to get there. That path is important, because the pipeline could contain other things. For example, consider this command (which you re welcome to try):
PS C:\> write-output "Hello" | where-object { $_.length -gt 10 }
Figure 16.5 WriteOutput puts objects into the pipeline, which in some cases will eventually result in those objects being displayed.
Input and output
Figure 16.6 Placing objects into the pipeline means they can be filtered out before they re displayed.
There s no output from this command, and figure 16.6 illustrates why. "Hello" was placed into the pipeline. Before it got to Out-Default, however, it had to pass through Where-Object, which filtered out anything having a Length property of less than or equal to 10, which in this case included our poor "Hello". So our "Hello" got dropped out of the pipeline. There was nothing left in the pipeline for Out-Default, so there was nothing to pass to Out-Host, so nothing was displayed. Contrast that command with this one:
PS C:\> write-host "Hello" | where-object { $_.length -gt 10 } Hello
All I did was replace Write-Output with Write-Host. This time, "Hello" went directly to the screen, not into the pipeline. Where-Object had no input, and produced no output, so nothing was displayed by Out-Default and Out-Host. But because "Hello" had been written directly to the screen, we saw it anyway. Write-Output may seem new, but it turns out you ve been using it all along. It s the shell s default cmdlet. When you tell the shell to do something that isn t actually a command, the shell passes whatever you typed to Write-Output behind the scenes.
16.5 Other ways to write
PowerShell has a few other ways of producing output. None of these write to the pipeline like Write-Output does; they work a bit more like Write-Host. All of them, however, produce output in a way that can be suppressed. The shell comes with built-in configuration variables for each of these alternative output methods. When the configuration variable is set to Continue, the commands I m about to show you do indeed produce output. When the configuration variable is
set to SilentlyContinue, the associated output command produces nothing. Table 16.1 contains the list of commands.
Table 16.1 Alternative output cmdlets Purpose Displays warning text, in yellow by default and preceded by the label WARNING: Displays additional informative text, in yellow by default and preceded by the label VERBOSE: Displays debugging text, in yellow by default and preceded by the label DEBUG: Produces an error message Configuration variable $WarningPreference (Continue by default) $VerbosePreference (SilentlyContinue by default)
Copyright © OnBarcode.com . All rights reserved.