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

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balubeto Posted: 09-05-2010 5:13 AM

rated by 0 users

HI

The script:

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

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"
}

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

THANKS

BYE

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balubeto replied on 09-08-2010 5:15 AM

rated by 0 users

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
}

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

THANKS

BYE

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balubeto replied on 09-08-2010 11:26 AM

rated by 0 users

In Windows 7, the symbols that can not be used in the usernames are only /\[]":;<>+=,?*

If this is true, how can I check if a name of a user contains all the symbols allowed by Windows 7 (multilingual) except the symbols listed above?

THANKS

BYE

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balubeto replied on 09-10-2010 4:31 AM

rated by 0 users

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

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balubeto replied on 09-12-2010 2:24 PM

rated by 0 users

It is possible to improve the look of the condition of the IF structure of this script?

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

if (($username.length -ge 1) -and -not(([regex]::isMatch($username,'^\s|\s$|^(\.|\s)+$|.{21,}|[\\/"\[\]:\|<>\+=;,\?\*@]')))) {
 Write-Host "Username '$UserName' is valid"
}
else {
 Write-Host "Username '$UserName' is invalid"
}

In other words, what is the opposite of the ^\s|\s$|^(\.|\s)+$|.{21,}|[\\/"\[\]:\|<>\+=;,\?\*@] expression to remove at least the -not operator?

THANKS

BYE

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balubeto replied on 09-13-2010 1:20 PM

rated by 0 users

I think I found a more elegant solution or there is another even better solution than this:

$UserName = Read-Host "Checking the validity of the username"
if ( ($username.length -ge 1) -and ($UserName -notmatch '^\s|\s$|^(\.|\s)+$|.{21,}|[\\/"\[\]:\|<>\+=;,\?\*@]') ) {
 Write-Host "Username '$UserName' is valid"
}
else {
 Write-Host "Username '$UserName' is invalid"
}

By chance, someone sees bugs in this script?

THANKS

BYE

Reply

balubeto replied on 09-13-2010 1:22 PM

rated by 0 users

I think I found a more elegant solution or there is another even better solution than this:

$UserName = Read-Host "Checking the validity of the username"
if ( ($username.length -ge 1) -and ($UserName -notmatch '^\s|\s$|^(\.|\s)+$|.{21,}|[\\/"\[\]:\|<>\+=;,\?\*@]') ) {
 Write-Host "Username '$UserName' is valid"
}
else {
 Write-Host "Username '$UserName' is invalid"
}

By chance, someone sees bugs in this script?

THANKS

BYE