MacOS – Enable Web Inspector in Safari v 8.0 in Yosemite OS

You can use the run handler to pass arguments:

dialog() {
    osascript -e 'on run args
    try
    tell app "SystemUIServer" to display dialog (item 1 of args)
    end
    activate app (path to frontmost application as text)
    end' "$1"
}

If you want to call it like dialog a b (instead of dialog 'a b'), change $1 to $*.

System Events quits automatically when it is not used, and there is a small delay when it is opened, so telling it to display the dialog would sometimes be slower.

Without the try block there would be an error if the user presses a cancel button. Without activate the previously focused window wouldn't get focus back when the dialog is closed.

You can use something like this to display text dialogs:

answer=$(osascript -e 'try
tell app "SystemUIServer"
set answer to text returned of (display dialog "" default answer "")
end
end
activate app (path to frontmost application as text)
answer' | tr '\r' ' ')
[ -z "$answer" ] && exit

If anyone else needs to do this, here is the solution I came up with:

#!/bin/bash

VM="name of my VM"
CMD="prlctl exec \"$VM\" ipconfig | grep "IPv4" | grep -m1 -o '\d\{1,3\}\.\d\{1,3\}\.\d\{1,3\}\.\d\{1,3\}'"
IP=$(eval $CMD)

#once you have the correct data in the $IP variable you can do something with it.. I initiate an ssh session, but you can do whatever you like.

I have no idea why eval is needed here. Someone more familiar with bash will be needed to answer that mystery.