Extension for temporary files
When I did the post on creating temporary files http://msmvps.com/blogs/richardsiddaway/archive/2009/11/05/creating-temporary-files.aspx I said I’d modify it so the file would be created with a given extension.
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| ## asssume that want temp files in multiples of 1KB or empty
## renaming Get-ChildItem -Path c:\test\test2 | Rename-Item -NewName {$_.Name -replace "\....", ".txt"}
function New-TempFile {
param (
[string]$path = "C:\Test",
[int]$size = 1KB,
[string]$ext = ""
)
if (!(Test-Path -Path $path)){throw "Invalid path"}
$file = [System.IO.Path]::GetRandomFileName()
if ($ext -ne "") {
if ($ext.StartsWith(".")){$ext = $ext.Remove(0,1)}
$file = $file -replace "\....", ".$ext"
}
if ($size -eq 0){
New-Item -Path $path -Name $file -ItemType 'File'
}
else {
$data = "*" * 128
$lines = [System.Math]::Ceiling(($size / 1kb) * 8)
for ($i=1; $i -le $lines; $i++){
Add-Content -Path $(Join-Path -Path $path -ChildPath $file) -Value $data
}
Get-ChildItem -Path $path -Filter $file
}
} |
It just involves adding another parameter $ext with a default empty string value. If we give an extension
New-TempFile -size 2kb -ext "txt" -path "c:\test\test2"
Then we test to see if it starts with a . and remove it. We then replace the extension of the randomly generated filename using a regular expression match on the extension [ the regex is translated as 3 characters following a . The \ is an escape character so . is read literally rather than as a wildcard]
Everything else is the same. One other thing I might do is change the way data is put into the files. For larger files its slow so I might do something different there. This is one of great features of working with PowerShell like this – I can get a working script quickly and then refine it over time as I get chance to think about it. Because I can work interactively at the prompt I can quickly test ideas before changing the script.