There is a function to separate

Question

I've been looking for a function to separate and I found -split but I do not know how to apply it. I want to separate this file in 4 parts (result) but I do not know how to do it.

192_168_249_1_01_22_2019_01_38_55.txt

Result that I want you to have:

192.168.246.1
22-22-2019
01:38:55
.TXT

Answer 1

Another approach would be to use Regular Expression to get the different parts of the filename.
Something like this perhaps:

function Split-FileName {
    param ([string]$FileName)
    if ($FileName -match '^(?<ip>(?:\d{1,3}_){3}\d{1,3})_(?<date>(?:\d{1,2}_){2}\d{4})_(?<time>(?:\d{1,2}_){2}\d{1,2})(?<ext>\.\w+)') {
        [PSCustomObject]@{
            IPAddress = $matches['ip'] -replace '_', '.'
            Date =      $matches['date'] -replace '_', '-'
            Time =      $matches['time'] -replace '_', ':'
            Extension = $matches['ext'].ToUpper()
        }
    }
}

Use it like this:

Split-FileName '192_168_249_1_01_22_2019_01_38_55.txt'

To return an object with all 4 parts in the wanted format (by default as Table)

IPAddress     Date       Time     Extension
---------     ----       ----     ---------
192.168.249.1 01-22-2019 01:38:55 .TXT

or as list if you do

Split-FileName '192_168_249_1_01_22_2019_01_38_55.txt' | Format-List

IPAddress : 192.168.249.1
Date      : 01-22-2019
Time      : 01:38:55
Extension : .TXT

Regex Details

^                 Assert position at the beginning of a line (at beginning of the string or after a line break character)
(?<ip>            Match the regular expression below and capture its match into backreference with name “ip”
   (?:            Match the regular expression below
      \d          Match a single digit 0..9
         {1,3}    Between one and 3 times, as many times as possible, giving back as needed (greedy)
      _           Match the character “_” literally
   ){3}           Exactly 3 times
   \d             Match a single digit 0..9
      {1,3}       Between one and 3 times, as many times as possible, giving back as needed (greedy)
)
_                 Match the character “_” literally
(?<date>          Match the regular expression below and capture its match into backreference with name “date”
   (?:            Match the regular expression below
      \d          Match a single digit 0..9
         {1,2}    Between one and 2 times, as many times as possible, giving back as needed (greedy)
      _           Match the character “_” literally
   ){2}           Exactly 2 times
   \d             Match a single digit 0..9
      {4}         Exactly 4 times
)
_                 Match the character “_” literally
(?<time>          Match the regular expression below and capture its match into backreference with name “time”
   (?:            Match the regular expression below
      \d          Match a single digit 0..9
         {1,2}    Between one and 2 times, as many times as possible, giving back as needed (greedy)
      _           Match the character “_” literally
   ){2}           Exactly 2 times
   \d             Match a single digit 0..9
      {1,2}       Between one and 2 times, as many times as possible, giving back as needed (greedy)
)
(?<ext>           Match the regular expression below and capture its match into backreference with name “ext”
   \.             Match the character “.” literally
   \w             Match a single character that is a “word character” (letters, digits, etc.)
      +           Between one and unlimited times, as many times as possible, giving back as needed (greedy)
)

Answer 2

You can try to use a function like this:

function get-split {
    param([string]$text)
    ($text.Split("_"))[0..3] -join "."
    ($text.Split("_"))[4..6] -join "-"
    (($text.Split("_"))[7..9] -join ":").split(".")[0]
    ".$((($text.Split("_"))[7..9] -join ":").split(".")[1])"
}

I know that it can be improved, but works I think...