I am trying to set up a PowerShell script to change the date within a file whenever it is run. Below is the current code. It looks for regex with an existing date to replace. I don't know if my regex is correct, but it should check for a date in the format of MM.dd.yy i.e. 10.12.22 for October 12, 2022.

$regexDate = '^\d{4}\-(0?[1-9]|1[012])\-(0?[1-9]|[12][0-9]|3[01])$'
$currentDate = Get-Date -UFormat "%m.%d.%y"

Get-Content -path "template1.dat" | % { $_ -Replace $regexDate, $currentDate } |  Out-File "template1.dat"

Example input file:

Date: 10.12.22

Lorem ipsum dolor sit amet, consectetur adipiscing elit.

Quam adipiscing vitae proin sagittis nisl rhoncus. 

Placerat orci nulla pellentesque dignissim enim sit amet venenatis.

CodePudding user response：

The date format in your file is with 2 digits at the end for the year, instead of 4 digits (also not at the start of the string with the ^ anchor)

\b(?:0?[1-9]|1[012])\.(?:0?[1-9]|[12][0-9]|3[01])\.\d\d\b

Or change the \b at the end to $ for the end of the string.

Regex demo

CodePudding user response：

Without regex, what about this ?

$pathtofile = "Path to file"
$contenttokeep = Get-Content -LiteralPath $pathtofile | Select-Object -Skip 1

(Get-Date -UFormat "%m.%d.%y") | Out-File -LiteralPath $pathtofile
$contenttokeep | Out-File -LiteralPath $pathtofile -Append