automated folder structure creation with conditions - powershell

Question

any idea / suggestion how to simplify this code? I would like to find different approach to create folders as they need to be created.
function TargetDir { # create folder structure for patches by OS type
if ($col6 -like "*WindowsXP*" -or $col4 -like "*Windows XP*"
) {$TargetDir = "$Path\$col1\XP"
if (!(Test-Path -path $TargetDir
)) {New-Item $Path\$col1\XP -type directory
New-Item -type file -Name $Col6 -Path $TargetDir}
else {New-Item -type file -Name $Col6 -Path $TargetDir}
}
elseif ($col6 -like "*Windows6.0*" -or $col4 -like "*Vista*"
) {$TargetDir = "$Path\$col1\Vista"
if (!(Test-Path -path $TargetDir
) ) {New-Item $Path\$col1\Vista -type directory
New-Item -type file -Name $Col6 -Path $TargetDir}
else {New-Item -type file -Name $Col6 -Path $TargetDir}
}
elseif ($col6 -like "*Windows6.1*" -or $col4 -like "*Windows 7*"
) {$TargetDir = "$Path\$col1\Win7"
if (!(Test-Path -path $TargetDir
) ) {New-Item $Path\$col1\Win7 -type directory
New-Item -type file -Name $Col6 -Path $TargetDir}
else {New-Item -type file -Name $Col6 -Path $TargetDir}
}
elseif ($col6 -like "*Windows8-RT*" -or $col4 -like "*Windows 8 *"
) {$TargetDir = "$Path\$col1\Win8"
if (!(Test-Path -path $TargetDir)
) {New-Item $Path\$col1\Win8 -type directory
New-Item -type file -Name $Col6 -Path $TargetDir}
else {New-Item -type file -Name $Col6 -Path $TargetDir}
}
elseif ($col6 -like "*Windows8.1*" -or $col4 -like "*Windows 8.1*"
) {$TargetDir = "$Path\$col1\Win81"
if (! (Test-Path -path $TargetDir)
) {New-Item $Path\$col1\Win81 -type directory
New-Item -type file -Name $Col6 -Path $TargetDir}
else {New-Item -type file -Name $Col6 -Path $TargetDir}
}
} # end if
Thank you for any suggestion how this could be simplified.

Answer 1

When you find yourself using elseif a lot switch might be there to save you.
You are checking if $col4 or $col6 has a match correct? Since that appears the case you only really need to check one of those values as long as it is not blank (Just bear with me). Also to make your function more portable (if not for you then for others) then we are going to use function parameters.
function Get-TargetDirectory{
param(
[string]$value1,
[string]$value2,
[string]$path,
[string]$directory
)
If($value1){$toMatch = $value1} #The value of $value1 is tested to contain a non empty string / null
If($value2){$toMatch = $value2} #The value of $value2 is tested to contain a non empty string / null
switch -Regex ($toMatch){
"Windows ?XP"{$TargetDir = "$Path\$directory\XP"}
"(Windows6\.0|Vista)"{$TargetDir = "$Path\$directory\Vista"}
"(Windows6\.1|Windows 7)"{$TargetDir = "$Path\$directory\Win7"}
"Windows ?8"{$TargetDir = "$Path\$directory\Win8"}
"Windows ?8\.1"{$TargetDir = "$Path\$directory\Win81"}
default{$TargetDir = ""}
}
If($TargetDir){ #The value of $TargetDir is tested to contain a non empty string / null
# Create the directory if it does not already exist
If(!(Test-Path -path $TargetDir)){[void](New-Item $TargetDir -type Directory)}
# Create the empty file in $TargetDir
New-Item -type file -Name $value1 -Path $TargetDir
}
}
I changed the names in my function to be more friendly. The following is how they map to your previous names.
Yours Get-TargetDirectory
$col1 $directory
$col4 $value2
$col6 $value1
$path $path
Not perfect as there are some caveats that you dont already account for like the presence of the folder I refer to as $directory. Using the -Regex keyword we can simplify the match operations. Also, there is no need to have the code to create items exist multiple times since it will be called regardless.
Hopefully this, untested code, works for you and shows you some good coding practices.

Answer 2

Matt thank you for your replay. I admit that I shared almost non detail but I had on my mind something much more simpler... Your suggestion to use switch was the key to get it done that way.
switch -wildcard ($FileName)
{
"*6.0*" { $TargetDir = "$Path\Vista\" }
"*6.1*" { $TargetDir = "$Path\Windows 7\" }
"*8-R*" { $TargetDir = "$Path\Windows 8\" }
"*8.1*" { $TargetDir = "$Path\Windows 8.1\" }
default { write-host "Define target directory for $FileName" -foreground "red"}
}
if (Test-Path -path $TargetDir) {
New-Item $TargetDir -type directory
New-Item -type file -Name $FileName -Path $TargetDir
} else {
New-Item -type file -Name $FileName -Path $TargetDir -Force
}