[PS] Checking a valid local user name of an account in Windows 7

HI

The script:

if( $UserName -notmatch "\W") {
   Write-Host "Username '$UserName' is valid"
}
Else {
   Write-Host "Username '$UserName' is invalid"
}

Code (markup):

works, but, if a user does not insert any characters, the script writes: "Username '' is valid" Why?

Instead, this script:

 If ( (([adsi]("WinNT://[Environment]::MachineName,computer")).children | ? {$_.psbase.schemaClassName -eq "User"} | Select -expand Name) -contains $UserName) {
    Write-host "$UserName exists"
}
else {
    Write-host "$UserName not exists"
}

Code (markup):

does not work because it always writes that the user inserted does not exist. Why?

THANKS

BYE

 

hmm, is this a batch script?

 

I noticed that the script:

$UserName   = Read-Host "Checking the validity of the username"

if ( $UserName -match "^\w{1,19}$" )     #Please note the lowercase w, means: 1 to 19 characters of the character class [a-zA-Z0-9_]
{
 Write-Host -Foreground green "Username '$UserName' is valid"    #Now we take the valid case in the IF clause because it is easier to write 
}
else
{
 Write-Host -Foreground red "Username '$UserName' is invalid"    # and the invalid case in the ELSE clause
}

Code (markup):

writes "Username $username is invalid" when I write an username that contains spaces. Why?

THANKS

BYE

 

The "^[\w+\p{L}\s-]{1,17}$" expression works well, but unfortunately, it also validates the usernames that begin or end with spaces. So, how could I fix this?

In Windows 7, what is the maximum length for the usernames?

THANKS

BYE