powershell - Change Letter inside a test file

Question

I have a file that has character that deems it production or test.

P=production T=test

select-string "\myfileserverfiles999.80214.va.000000373.20210122.173314.20210755" -pattern "T"

The above returns a True. I need to change that T to a P in the file

999.80214.va.000000373.20210122.173314.20210755:1:ISA*00* 00 ZZ*83-1002042 *ZZ*841469824 *210 123*0753*$*00501*000000209*0*T:

How do I search for the T in this string

question from:https://stackoverflow.com/questions/65933101/change-letter-inside-a-test-file

Answer 1

OK, with all the necessary infomration we gathered step by step I'd come up with this simple solution:

$Path = '\myfileserverfiles999.80214.va.000000373.20210122.173314.20210755'
$Content = Get-Content -Path $Path
$NewContent = 
(($Content | Select-Object -First 1) -replace '(?<=*)T(?=:$)','P'),
($Content | Select-Object -Skip 1)
Set-Content -Path $Path -Value $NewContent

It takes the content of the file, changes only the first line, combines this new first line with the original unchanged rest of the file and writes it back to the original file.