How to use dash or hyphen to join a string array in Powershell - string

Question

I wrote code like this:
$count = 0
$path = "C:\Videos\"
$oldvids = Get-ChildItem -Path $path -Include *.* -Recurse
foreach ($oldvid in $oldvids) {
$curpath = $oldvid.DirectoryName
$name = [System.IO.Path]::GetFileNameWithoutExtension($oldvid)
$names = $name.Split(" - ")
$names[0] = ""
$metadata_title = $names -join "-"
$ext = [System.IO.Path]::GetExtension($oldvid)
if ($name.StartsWith("new_") -eq $false)
{
$newvid = $curpath + "/new_" + $name + ".mp4"
if ([System.IO.File]::Exists($newvid) -eq $false)
{
$count++
Write-Output $metadata_title
}
}
}
But this code causes a file name like this:
Chapter 1 - New Video
to become:
Chapter 1---New Video
How can I make sure a single - is actually only one? Do I have to escape it?
The idea is to eliminate first part of the file names, so from:
01 - Chapter 1 - Video 1
to:
Chapter 1 - Video 1
So I wanted to split using " - " and then join everything back without the first element in the split array.

Answer 1

Looking at your example and your explanation of changing metadata with ffmpeg on each file, I guess this is what you need:
$count = 0
$path = 'C:\Videos'
# get a list of old video files (these do not start with 'new_')
$oldvids = Get-ChildItem -Path $path -Filter *.mp4 -File -Recurse |
Where-Object { $_.Name -notmatch '^new_' }
foreach ($oldvid in $oldvids) {
# if the file is called 'C:\Videos\01 - Chapter 1 - Video 1.mp4'
$tempName = $oldvid.Name -replace '^\d+\s*-\s*(.+)', 'new_$1' # --> new_Chapter 1 - Video 1.mp4
# or do
# $tempName = 'new_' + ($oldvid.Name -split '-', 2)[-1].Trim() # --> new_Chapter 1 - Video 1.mp4
# or
# $tempName = $oldvid.Name -replace '^\d+\s*-\s*', 'new_' # --> new_Chapter 1 - Video 1.mp4
# combine the current file path with the temporary name
$outputFile = Join-Path -Path $oldvid.DirectoryName -ChildPath $tempName
#######################################################################
# next do your ffmpeg command to change metadata
# for input you use $oldvid.FullName and for output you use $outputFile
Write-Host "Updated file $($oldvid.Name) as $tempName"
#######################################################################
# when done with ffmpeg, delete the original (or for safety move it to somewhere else)
Write-Host "Deleting file '$($oldvid.Name)'"
$oldvid | Remove-Item -WhatIf
# and rename the updated file by removing the 'new_' part from its name
$newName = ($tempName -replace '^new_').Trim()
Write-Host "Renaming updated file to '$newName'"
$tempName | Rename-Item -NewName $newName
# all done, proceed with the next file
$count++
}
Note: I have added switch -WhatIf to the Remove-Item line. This is a safety measure that will only display what file would be deleted without actually deleting it.
If you are sure the correct file should be deleted, then remove that -WhatIf switch so the original file gets destroyed after maipulating it with ffmpeg.
As per your comment, to send items to the Recycle bin instead of destroying them like Remove-Item does, here's two ways of achieving that:
Method 1: Use COM
function RemoveTo-RecycleBin {
[CmdletBinding()]
param (
[Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)]
[Alias('FullName')]
[string[]]$Path
)
begin {
$shell = New-Object -ComObject 'Shell.Application'
$Recycler = $Shell.NameSpace(0xa)
}
process {
foreach ($item in $Path) {
[void]$Recycler.MoveHere($item)
}
}
end {
# clean-up the used COM objects
$null = [System.Runtime.Interopservices.Marshal]::ReleaseComObject($Recycler)
$null = [System.Runtime.Interopservices.Marshal]::ReleaseComObject($shell)
$null = [System.GC]::Collect()
$null = [System.GC]::WaitForPendingFinalizers()
}
}
# usage example, remove all files from the D:\Test directory
Get-ChildItem -Path 'D:\Test' -Filter '*.*' -File | RemoveTo-RecycleBin
# usage example, remove all files and subdirectories from the D:\Test directory
Get-ChildItem -Path 'D:\Test' | RemoveTo-RecycleBin
Method 2: Use the Microsoft.VisualBasic assembly
function RemoveTo-RecycleBin {
[CmdletBinding()]
param (
[Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)]
[Alias('FullName')]
[string[]]$Path,
[switch]$ShowConfirmationDialog
)
begin {
Add-Type -AssemblyName Microsoft.VisualBasic
$showUI = if ($ShowConfirmationDialog) { 'AllDialogs' } else { 'OnlyErrorDialogs' }
}
process {
foreach ($item in $Path) {
Write-Host $item
# detect if this is a file or a directory
if ((Get-Item -Path $item) -is [System.IO.DirectoryInfo]) {
# first parameter: the absolute full path
# second parameter: one of Microsoft.VisualBasic.FileIO.UIOption values: OnlyErrorDialogs or AllDialogs
# third parameter: one of Microsoft.VisualBasic.FileIO.RecycleOption values: DeletePermanently or SendToRecycleBin
[Microsoft.VisualBasic.FileIO.FileSystem]::DeleteDirectory($item, $showUI, 'SendToRecycleBin')
}
else {
# first parameter: the absolute full path and file name
# second parameter: one of Microsoft.VisualBasic.FileIO.UIOption values: OnlyErrorDialogs or AllDialogs
# third parameter: one of Microsoft.VisualBasic.FileIO.RecycleOption values: DeletePermanently or SendToRecycleBin
[Microsoft.VisualBasic.FileIO.FileSystem]::DeleteFile($item,$showUI, 'SendToRecycleBin')
}
}
}
}
# usage example, remove all files from the D:\Test directory
Get-ChildItem -Path 'D:\Test' -Filter '*.*' -File | RemoveTo-RecycleBin
# usage example, remove all files and subdirectories from the D:\Test directory
Get-ChildItem -Path 'D:\Test' | RemoveTo-RecycleBin
Just choose any of the above functions, put it on top of your script and then change line
$oldvid | Remove-Item -WhatIf
into
$oldvid | RemoveTo-RecycleBin