{"id":12191,"date":"2011-11-04T00:01:00","date_gmt":"2011-11-04T00:01:00","guid":{"rendered":"https:\/\/blogs.technet.microsoft.com\/heyscriptingguy\/2011\/11\/04\/use-a-csv-file-to-populate-parameters-of-powershell-cmdlets\/"},"modified":"2011-11-04T00:01:00","modified_gmt":"2011-11-04T00:01:00","slug":"use-a-csv-file-to-populate-parameters-of-powershell-cmdlets","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/scripting\/use-a-csv-file-to-populate-parameters-of-powershell-cmdlets\/","title":{"rendered":"Use a CSV File to Populate Parameters of PowerShell Cmdlets"},"content":{"rendered":"

Summary:<\/strong> Learn how to use a CSV file to populate parameters of Windows PowerShell cmdlets.<\/span><\/span><\/p>\n

 <\/span><\/p>\n

\"Hey,<\/span><\/span><\/span><\/span><\/span>Hey, Scripting Guy! I have a problem. I would like to be able to read content from a comma-separated value (CSV) file that contains a list of WMI classes and servers that I would like to query. I need to be able to read the CSV file, and based upon the data contained in that CSV file, I need to create a query on the fly and execute that query. I am afraid it is too complicated, but if I can do this, it will make things a whole lot easier for us at work. Do you know any secret tricks to help us out of our dilemma? <\/span><\/p>\n

—SC<\/span><\/p>\n

 <\/span><\/p>\n

\"Hey,<\/span><\/span><\/span><\/span>Hello SC, <\/span><\/p>\n

Microsoft Scripting Guy Ed Wilson here. Getting to go to different places and talk to people about Windows PowerShell is a lot of fun. However, there is a downside—expense reports. I wish there were a Windows PowerShell cmdlet called Get-Expense<\/b>, and another one called New-ExpenseReport<\/b>. If there were, I could use a command such as this one:<\/span><\/p>\n

Get-Expense | New-ExpenseReport<\/span><\/p>\n

That is the beauty of the Windows PowerShell pipeline. It looks at incoming properties, and seems to match them with similar items on the other side. Therefore, I can easily type the following:<\/span><\/p>\n

Get-Process | Stop-Process<\/span><\/p>\n

And the command works. This is a really cool example because the Get-Process<\/b> default property is name<\/b> <\/i>and the default property for Stop-Process<\/b> is id<\/b>. <\/i>The Windows PowerShell pipeline figures this stuff out. Cool. <\/span><\/p>\n

If a cmdlet or advanced function does not accept piped input, all is not lost because you can always use the Foreach-Object<\/b> cmdlet and manually map things inside that cmdlet’s scriptblock. <\/span><\/p>\n

The key here is that when importing a CSV file via the Import-CSV<\/b> cmdlet, each column becomes a property of an object. The other key here is that in a pipeline situation, $_<\/b> refers to the current item on the pipeline. <\/span><\/p>\n

Using this as background, I want to look at a sample CSV file such as you described. The first column contains a WMI class name, and the second column is the computer name to use. The sample CSV file is shown in the following figure.<\/span><\/p>\n

\"Image<\/a><\/span><\/p>\n

The following steps are required to read a CSV file and create a WMI query.<\/span><\/p>\n

    \n
  1. Use the Import-CSV<\/b> cmdlet to import the CSV file.<\/span><\/span><\/li>\n
  2. Use the ForEach-Object<\/b> cmdlet to walk through the imported data as it comes across the pipeline.<\/span><\/span><\/li>\n
  3. Inside the script block of the Foreach-Object<\/b> cmdlet, use the Get-WMIObject<\/b> cmdlet to query WMI.<\/span><\/span><\/li>\n
  4. Map the CSV column headings to the parameters of the Get-WmiObject<\/b> cmdlet.<\/span><\/span><\/li>\n
  5. Use the $_<\/b> variable to refer to the current items on the pipeline.<\/span><\/span><\/li>\n<\/ol>\n

    The command to read a CSV file named WMICSVFile.csv that resides in the C:\\fso directory and to query WMI is shown here (in the following command, %<\/b> is an alias for the Foreach-Object<\/b> cmdlet, and gwmi<\/b> is an alias for the Get-WmiObject<\/b> cmdlet):<\/span><\/p>\n

    import-csv C:\\fso\\WMICSVFile.csv | % {gwmi $_.class -cn $_.cn}<\/span><\/p>\n

    The command to read a CSV file and automatically query WMI along with the associated output is shown in the following figure.<\/span><\/p>\n

    \"Image<\/a><\/span><\/p>\n

     <\/span><\/p>\n

    SC, that is all there is to using a CSV file for input to other commands. This also concludes CSV Week. Join me tomorrow for the Weekend Scripter.<\/span><\/p>\n

    I invite you to follow me on <\/span>Twitter<\/span><\/a> and <\/span>Facebook<\/span><\/a>. If you have any questions, send email to me at <\/span>scripter@microsoft.com<\/span><\/a>, or post your questions on the <\/span>Official Scripting Guys Forum<\/span><\/a>. See you tomorrow. Until then, peace.<\/span><\/span><\/p>\n<\/p>\n

    Ed Wilson, Microsoft Scripting Guy<\/b><\/span><\/p>\n

    <\/span> <\/p>\n

     <\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

    Summary: Learn how to use a CSV file to populate parameters of Windows PowerShell cmdlets.   Hey, Scripting Guy! I have a problem. I would like to be able to read content from a comma-separated value (CSV) file that contains a list of WMI classes and servers that I would like to query. I need […]<\/p>\n","protected":false},"author":596,"featured_media":87096,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[169,3,4,45,6],"class_list":["post-12191","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-scripting","tag-csv-and-other-delimited-files","tag-scripting-guy","tag-scripting-techniques","tag-windows-powershell","tag-wmi"],"acf":[],"blog_post_summary":"

    Summary: Learn how to use a CSV file to populate parameters of Windows PowerShell cmdlets.   Hey, Scripting Guy! I have a problem. I would like to be able to read content from a comma-separated value (CSV) file that contains a list of WMI classes and servers that I would like to query. I need […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/12191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/users\/596"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/comments?post=12191"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/12191\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media\/87096"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media?parent=12191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/categories?post=12191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/tags?post=12191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}