To check if a file is empty in PowerShell, get the file with Get-Item and test whether its Length is 0. Length is the file’s size in bytes: Output: Folders need a different test, which I cover further down. I ran every example in PowerShell 7.6 and Windows PowerShell 5.1 against the same sample folder, … Read more
To unblock files recursively in PowerShell, list every file in the folder with Get-ChildItem -Recurse and pipe them to Unblock-File: Only do this for files you trust. Below I show how Windows marks downloads, how to find blocked files first, and how to unblock only scripts, all tested in PowerShell 7.6 and 5.1. Why Windows … Read more
To convert an array to a string in PowerShell, use the -join operator with the separator you want between the items: Output: -join works with any separator, including none. It’s the method I’d reach for first, because it’s short, clear and works the same in every PowerShell version. I ran every example in PowerShell 7.6 … Read more
To find and replace text in a file with PowerShell, read the file with Get-Content in parentheses, use -replace, and write it back with Set-Content: Output (the new file content): The parentheses matter, and so do a few other details that quietly damage files. I ran every example in PowerShell 7.6 and Windows PowerShell 5.1 … Read more
In PowerShell, try/catch runs the code in try and jumps to catch when a terminating error happens. For cmdlets, add -ErrorAction Stop so their errors reach the catch block: Output: Inside catch, $_ is the error record, and $_.Exception.Message is the readable message. Below I explain why catch sometimes doesn’t run, catch specific error types, … Read more
To compare strings in PowerShell, use -eq for equal and -ne for not equal. Both ignore case, so add a c for a case-sensitive comparison, like -ceq: Output: I ran every example in PowerShell 7.6 and Windows PowerShell 5.1. Everything matched except one .NET method overload, which I point out below. Case-sensitive and case-insensitive comparison … Read more
In PowerShell, an if statement runs a block of code when its condition is true. Add elseif for more conditions and else for everything else. The condition goes in parentheses and the code in braces: Output: PowerShell checks each condition from the top and runs only the first block that’s true. I ran every example … Read more
To trim a string in PowerShell, call .Trim() to remove spaces from both ends, or .TrimStart() and .TrimEnd() for one side only: Output: Below I cover trimming specific characters, the first or last few characters, and text before or after a character. I ran every example in PowerShell 7.6 and Windows PowerShell 5.1, and I … Read more
ForEach-Object runs a script block once for every object that comes down the pipeline. Inside the block, $_ is the current object: Output: $PSItem is another name for $_, if you find it easier to read. I ran every example in PowerShell 7.6 and Windows PowerShell 5.1, and I note where they differ. Work with … Read more
To convert a string to a Boolean in PowerShell, use [System.Convert]::ToBoolean(). It turns the text True or False into the matching Boolean value, ignoring case: Output: Don’t cast with [bool] for this. [bool]’False’ returns True, which I show next. I ran every example in PowerShell 7.6 and Windows PowerShell 5.1, with the same results. Why … Read more