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Guy's Top 10 Free Tools

1) FreePing
2) Network Monitor
3) Xobni
4) PuTTY (UNIX)
5) WMI Monitor
6) BgInfo
7) Net-SNMP
8) Engineer's Toolset
9) DNS Stuff
10) WinDiff

PowerShell Scripting  -WhatIf and -Confirm

Introduction to PowerShell Scripting -WhatIf and -Confirm

PowerShell's WhatIf and confirm are two great commands for testing complicated scripts without risking the code running amok.  For example, if you decide to delete files by using a script containing wildcards, there could be all manner of unexpected side effects.  By employing PowerShell, and appending -whatIf you get a preview of would happen without risking any damage.

PowerShell WhatIf and -Confirm Topics

• Mission to Delete Files
• PowerShell -whatIf Example
• PowerShell -confirm Example
• PowerShell Cmdlets Containing -Confirm and -WhatIf

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Mission to Delete Files

Let us take a real life example, we wish to delete files, but because we are using wildcards we are concerned about deleting the wrong type of file.  Instead of gung-ho Guy deleting the files - ready or not, we will take the cautious approach and append -whatIf.  The result is PowerShell completes the command and shows us the result, but does not delete any files.  Incidentally, I cannot find a delete verb in PowerShell, there is however, a remove verb.

PowerShell -whatIf Example

By adding -whatIf at the end of the command we are saying to PowerShell: 'Just test, don't actually make any permanent changes'.  Please note, there could be serious consequences if you don't use the -whatIf switch.  If you don't understand what you are doing, you could delete all your .txt files.

Note: For safety I chose a fictitious folder, just in case the script ran amok.

A breakdown of what the above script achieves

Get-Childitem  (Rather like dir)
c:\SomeFile (Location to start)
-include *.txt  (The pattern to look for)
-recurse (Search subdirectories)
| remove-Item (The equivalent of Delete)
-whatIf (PowerShell please test, but don't actually complete the operation, in this case, just show me which files with a .txt extension would be deleted if I removed the -whatIf).

Another example of -whatIf

PowerShell -confirm Example

Here is another PowerShell parameter that you append to a 'normal' script - confirm.  It really is a case of confirm by name, and confirm by nature.  PowerShell says to you: 'Do you really want to do this?'

Note: For safety I chose a fictitious folder, just in case the script went wrong.

The result of -confirm is that PowerShell presents you with choices, however, remember this is now 'live' therefore if you press [Y] or [A] then files will be deleted.

[Y] Yes [A] Yes to all  [N] No  [L] No to all [S] Suspend

How To Research PowerShell Cmdlets Containing -Confirm and -WhatIf

Refine Get-Command with -CommandType

Summary of PowerShell -whatIf and -confirm

Once you have used PowerShell's -confirm or -whatIf you will think, 'Why don't all scripting languages have these safety features'.

See more PowerShell examples for syntax advice

• PowerShell Tutorials  • Syntax  • PowerShell functions  • Plist  • RegEx  • -Com

• PowerShell -confirm  • WhatIf  • -Match  • -Online  • Where  • -ErrorAction  • -Replace

Please write in if you have a better example script. Also please report any factual mistakes, grammatical errors or broken links, I will be happy to correct the fault.

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