handling net use error messages with powershell - powershell

Question

I'm using a simple net use command to map a network drive
net use \\$HOSTIP $PASSWD /user:$UNAME
i must use net use instead of of New-PSDrive because the scripts runs for more then 400 machines in multiple instances and just wouldn't be doable.
I want to filter the error message then net use return like
System error 64 has occurred.
or
System error 67 has occurred.
How can I do this?

Answer 1

You can do the following:
#set process startup info (redirect stderr)
$pinfo = new-object System.Diagnostics.ProcessStartInfo
$pinfo.Filename = "net.exe"
$pinfo.UseShellExecute = $false
$pinfo.Arguments = #("use","\\$($HOSTIP)","$($PASSWD)","/user:$($UNAME)")
$pinfo.redirectstandardError = $true
#start process and wait for it to exit
$p = New-Object System.Diagnostics.Process
$p.StartInfo = $pinfo
$p.start() | out-null
$p.waitforexit()
#check the returncode
if($p.exitcode -ne 0){
#rc != 0 so we grab the stderr output
$err = $p.standardError.ReadToEnd()
#first line of the output contains the string from your question, matching it against regex
if($err[0] -match "System error ([0-9]*) has occurred"){
#switching the error code
switch($Matches[1]){
64 {do-something64;break;}
67 {do-something67;break;}
}
}
}
This should do the trick, although i cant make a statement about how performant it is, you will have to try. If the output can differ from the string you posted in your question you will have to write your own regexes to handle them.
Keep in mind that the output from net is localized so the regex in my example will not work on systems where the system language is not english.
Hope that helps

Answer 2

Use cmd to redirect stderr to stdout:
$log = cmd /c "2>&1" net use \\$HOSTIP $PASSWD /user:$UNAME
Now the variable contains an array of strings (2 with text and 2 empty):
System error 53 has occurred.
The network path was not found.
You can parse it:
$log = cmd /c "2>&1" net use \\$HOSTIP $PASSWD /user:$UNAME
if ($LASTEXITCODE -and $log -join "`n" -match '^.+?(\d+).+?\n+(.+)') {
$errCode = [int]$matches[1]
$errMessage = $matches[2]
}