Question

When do I need to surround strings in double quotes in PowerShell? Do I need all of these below?

& "$sendemail" -f "$sender" -t "$recipient" -u "$subject" -o message-file="$logpath" -s "$emailserver" -o tls=no

Answer 1

In this case you need none.

• $sendemail is hopefully already a string so the call operator & would work on it (maybe anything else would get coerced into a string anyway).

• All other variables should be passed correctly-quoted as well:

  PS> $subject = 'subject string'
  PS> $recipient = 'recipient string'
  PS> $logpath = 'log path'
  PS> $emailserver = 'email server'
  PS> $recipient = 'recipient''s name'
  PS> $sender = 'sender''s name'
  PS> $sendemail = './echoargs.exe'
  PS> & $sendemail -f $sender -t $recipient -u $subject -o message-file=$logpath -s $emailserver -o tls=no
  arg 1: -f
  arg 2: sender's name
  arg 3: -t
  arg 4: recipient's name
  arg 5: -u
  arg 6: subject string
  arg 7: -o
  arg 8: message-file=log path
  arg 9: -s
  arg 10: email server
  arg 11: -o
  arg 12: tls=no
  

You would need quotes if you want to pass literal strings that contain special characters (e.g. shell operators or spaces) to a program, e.g.:

./echoargs 'some spaces and a | pipe'

If all your arguments either do not contain such things or are already contained in a string variable themselves you’re good without quotes.