Get Maximum String-CodePudding

How would I get the file with the maximum date?

BACKUP-20220114.BAK
BACKUP-20220118.BAK
BACKUP-20220120.BAK

How would I select the file with the largest date value? I tried just finding the maximum string, but alas strings are not compared that way in powershell.

ls BACKUP* | select-object -Property Name | Measure-Object -Maximum
Measure-Object : Cannot compare "@{Name=BACKUP-20221028.bak}" because it is not IComparable.

How do I imbue the string with an IComparable?

CodePudding user response：

As per my comment.

(
$BackUpDates = @'
BACKUP-20220114.BAK
BACKUP-20220118.BAK
BACKUP-20220120.BAK
'@  | 
ConvertFrom-Csv -Header BackupDetail
)

# Results
<#
BackupDetail       
------------       
BACKUP-20220114.BAK
BACKUP-20220118.BAK
BACKUP-20220120.BAK
#>

$BackUpDates | 
Sort-Object -Property BackupDetail -Descending
# Results
<#
BackupDetail       
------------       
BACKUP-20220120.BAK
BACKUP-20220118.BAK
BACKUP-20220114.BAK
#>


$BackUpDates | 
Sort-Object -Property BackupDetail -Descending | 
Select-Object -First 1
# Results
<#
BackupDetail       
------------       
BACKUP-20220120.BAK
#>

Get-Content -path 'variable:\BackUpDates' | 
ConvertFrom-Csv -Header BackUpDate | 
Sort-Object -Property BackUpDate -Descending |
Select-Object -First 1
# Results
<#
BackUpDate         
----------         
BACKUP-20220120.BAK
#>

If you insist on using Measure-Command -Maximum, then a similar approach is:

(
Get-Content -path 'variable:\BackUpDates' | 
ConvertFrom-Csv -Header BackUpDate | 
Measure-Object -Property BackUpDate -Maximum
).Maximum
# Results
<#
BACKUP-20220120.BAK
#>