When I need to grab a device’s UDID, it has always felt heavy to me to have to launch iTunes or Xcode just to get a simple 40-character string. After years of sighing about it, I finally did something. Below is a simple bash script that uses mac OSes
system_profiler command to grab the UDIDs of any iOS devices connected to your computer. It will print all UDIDs to your terminal’s stdout and copy the last UDID to your clipboard for easy pasting.
Updated 9/24/18 to detect new 24 character UDIDs and insert a hyphen where Apple expects one.