Test-Path is the PowerShell cmdlet that checks whether a file, folder or other path exists. It returns True or False, so it drops straight into an if statement: Output: It never throws an error for a missing path, which makes it the safest check before you read, copy or delete something. I ran each example … Read more
To set the execution policy in PowerShell for your own account, run Set-ExecutionPolicy with RemoteSigned and the CurrentUser scope. It doesn’t need administrator rights: RemoteSigned runs scripts you write and blocks unsigned scripts from the internet. Below I check the current policy, change it for one session only, deal with blocked downloads and explain each … Read more
Format-Table is the PowerShell cmdlet that shows command output as a table. Pipe objects to it and list the properties you want as columns. All the examples below use this small list of servers: With no properties listed, Format-Table shows every property that fits: Output: I ran the examples in real PowerShell 7.6 and Windows … Read more
The PowerShell -match operator checks a string against a regular expression and returns True or False. When it matches, the matched text is saved in the automatic $Matches variable: Output: \d{4} means four digits, so the pattern finds the order number anywhere in the text. Below I cover case sensitivity, named groups, arrays, -notmatch, special … Read more
To find a string in a file and return the matching line in PowerShell, use Select-String with the file path and the text to look for. It returns the file name, the line number and the line itself: Output: Select-String works much like grep on Linux. I ran every example in PowerShell 7.6 and Windows … Read more
To extract text between two delimiters in PowerShell, match it with a regular expression and a capture group. The part in parentheses lands in $Matches[1]: Output: The ? after .* matters more than it looks, and -match only returns the first match. Both are covered below. I ran every example in PowerShell 7.6 and Windows … Read more
To restart a computer using PowerShell, run Restart-Computer. It restarts the local PC right away, so save your work first: Add -ComputerName to restart remote PCs. Below I preview restarts safely, restart remote servers and wait for them to come back, check for a pending restart and schedule one for later. Preview a restart with … Read more
In PowerShell, IsNullOrEmpty vs IsNullOrWhiteSpace comes down to how they treat spaces. IsNullOrEmpty only catches $null and empty strings, while IsNullOrWhiteSpace also catches strings made only of spaces, tabs or line breaks: For user input and data from files, IsNullOrWhiteSpace is almost always the one you want. Below are both checks side by side, a … Read more
To split a string in PowerShell, use the -split operator with the delimiter. It returns an array, with one item per piece: Output: PowerShell also has the .Split() string method. The two behave differently in a few important ways, and one of them changed between PowerShell versions. I ran every example in PowerShell 7.6 and … Read more
To convert a string to a binary number in PowerShell, turn the string into a number with [int], then call [Convert]::ToString($number, 2). The 2 means base 2, which is binary: Output: PadLeft adds leading zeros so every value has the same width. Below I also convert text to binary, binary back to decimal, and binary … Read more