power page 2 - Dave's Blog

Built-in

map

input | %{ expression($_) }

forEach

input | %{ [void]expression($_) }

filter

input | ?{ expression($_) }

indexOf

input.indexOf(value)

Close to built-in

some

if (input | ?{ expression($_) }) { ... }

every

if (-not input | ?{ !expression($_) }) { ... }

lastIndexOf

[array]::lastIndexOf(input, value)

Write it yourself

reduce

function reduce($fn, $a, $init) { $s = $init; $a | %{ $s = &$fn $s $_; }; $s; }

I wanted to ensure that my switch statement in my implementation of IInternetSecurityManager::ProcessURLAction had a case for every possible documented URLACTION. I wrote the following short command line sequence to see the list of all URLACTIONs in the SDK header file not found in my source file:

grep URLACTION urlmon.idl | sed 's/.*\(URLACTION[a-zA-Z0-9_]*\).*/\1/g;' | sort | uniq > allURLACTIONs.txt
grep URLACTION MySecurityManager.cpp | sed 's/.*\(URLACTION[a-zA-Z0-9_]*\).*/\1/g;' | sort | uniq > myURLACTIONs.txt
comm -23 allURLACTIONs.txt myURLACTIONs.txt

But in my effort to learn and use PowerShell I found the following similar command line:

diff 
(more urlmon.idl | %{ if ($_ -cmatch "URLACTION[a-zA-Z0-9_]*") { $matches[0] } } | sort -uniq) 
(more MySecurityManager.cpp | %{ if ($_ -cmatch "URLACTION[a-zA-Z0-9_]*") { $matches[0] } } | sort -uniq)

When you run clip.exe, whatever comes into its standard input is put onto the clipboard. So when you need to move the result of something in your command window somewhere else you can pipe the result into clip.exe. Then you won't have to worry about the irritating way cmd.exe does block copy/pasting and you avoid having to manually fixup line breaks in wrapped lines. For instance, you can put the contents of a script into the clipboard with:

more cdo.cmd | clip

I've got a lot of stuff dumped in my bin folder that I sync across all my PCs so I didn't realize that clip.exe is a part of standard Windows installs.

Nice for avoiding the block copy in cmd.exe but I'd prefer to have the contents sort of tee'd into the clipboard and standard output. So TeeClip.ps1:

$input | tee -var teeclipout | clip;
$teeclipout;

I'm trying to learn and use PowerShell more, but plenty of other folks I know don't use PowerShell. To allow them to use my scripts I use the following cmd.exe batch file to make it easy to call PowerShell scripts. To use, just name the batch file name the same as the corresponding PowerShell script filename and put it in the same directory.

@echo off
if "%1"=="/?" goto help
if "%1"=="/h" goto help
if "%1"=="-?" goto help
if "%1"=="-h" goto help

%systemroot%\system32\windowspowershell\v1.0\powershell.exe -ExecutionPolicy RemoteSigned -Command . %~dpn0.ps1 %*
goto end

:help
%systemroot%\system32\windowspowershell\v1.0\powershell.exe -ExecutionPolicy RemoteSigned -Command help %~dpn0.ps1 -full
goto end

:end

Additionally for PowerShell scripts that modify the current working directory I use the following batch file:

@echo off
if "%1"=="/?" goto help
if "%1"=="/h" goto help
if "%1"=="-?" goto help
if "%1"=="-h" goto help

%systemroot%\system32\windowspowershell\v1.0\powershell.exe -ExecutionPolicy RemoteSigned -Command . %~dpn0.ps1 %*;(pwd).Path 1> %temp%\%~n0.tmp 2> nul
set /p newdir=

For a new project I'm working on involving IE's installed Accelerators and OpenSearch search providers via the Windows 7 Accelerator Platform, I've created a C#/COM interop class for those APIs.

Download the osinterop.cs interop file here.

I've just got a new media center PC connected directly to my television with lots of HD space and so I'm ripping a bunch of my DVDs to the PC so I don't have to fuss with the physical media. I'm ripping with DVD Rip, viewing the results in Windows 7's Windows Media Center after turning on the WMC DVD Library, and using a powershell script I wrote to copy over cover art and metadata.

My powershell script follows. To use it you must do the following:

1. Run Windows Media Center with the DVD in the drive and view the disc's metadata info.
2. Rip each DVD to its own subdirectory of a common directory.
3. The name of the subdirectory to which the DVD is ripped must have the same name as the DVD name in the metadata. An exception to this are characters that aren't allowed in Windows paths (e.g. <, >, ?, *, etc)
4. Run the script and pass the path to the common directory containing the DVD rips as the first parameter.

Download copydvdinfo.ps1