powershell - Function search from the files 20.0.0.1 to 20.0.0.21

Question

I have 21 files from 20.0.0.0001 to 20.0.0.0021 in my directory D:Updates3 . I have a function "search" with 3 parameters: the directory, le first number of my file, the last number of my file My problem is when I enter the 3 parameters in my function search: the directory: D:Updates3 the first number: 20 the las number: 1 I have 3 results 20.0.0.0001 20.0.0.0011 20.0.0.0021

whereas, I want only the result 20.0.0.0001 What is the solution please?

here is my code:

$UpdatePath = "D:Updates3"

function search {
    param (
        [string]$UpdatePath,
        [int]$M,
        [int]$j
    )
    $UpdatePath = "D:Updates3"
    $Updates = (Get-ChildItem -Path $UpdatePath).BaseName
    
foreach ($item in $Updates) {
   
    if ($item -like "$M.0.0.???$j" ) {
        write-host $item
    }
}

}
search $Updates 20 1

question from:https://stackoverflow.com/questions/65947607/function-search-from-the-files-20-0-0-1-to-20-0-0-21

Answer 1

It is a pitty your function doesn't really return anything and only writes to the console the file(s) found. Why not turn this into a function that actually returns a FileInfo object you can get all kinds of properties from and if needed use its methods?

Also, try using the Powershell Verb-Noun naming convention for functions.

The below code doesn't cast the the basename of each file into a [version] type, but uses regex to both ensure the file's BaseName is in the format you describe, ignoring other files, but also it captures the first and last numbers to compare against:

function Find-File {
    param (
        [string]$Path,
        [int]$M,
        [int]$j
    )

    Get-ChildItem -Path $Path -File | 
        Where-Object {$_.BaseName -match '^(d+).d+.d+.(d+)$'} |
        Where-Object {[int]$matches[1] -eq $M -and [int]$matches[2] -eq $j}
}

# find and (if found) return the file as FileInfo object
$theFile = Find-File "D:Updates3" 20 1

Regex details

^            Assert position at the beginning of the string
(            Match the regular expression below and capture its match into backreference number 1
   d        Match a single digit 0..9
      +      Between one and unlimited times, as many times as possible, giving back as needed (greedy)
)            
.           Match the character “.” lterally
d           Match a single digit 0..9
   +         Between one and unlimited times, as many times as possible, giving back as needed (greedy)
.           Match the character “.” literally
d           Match a single digit 0..9
   +         Between one and unlimited times, as many times as possible, giving back as needed (greedy)
.           Match the character “.” literally
(            Match the regular expression below and capture its match into backreference number 2
   d        Match a single digit 0..9
      +      Between one and unlimited times, as many times as possible, giving back as needed (greedy)
)            
$            Assert position at the end of the string (or before the line break at the end of the string, if any)