A Jamf Pro extension attribute to return whether a user account (hidden or visible) in a list of user accounts exists on a computer.

Existing user accounts.zsh

#!/bin/zsh

:<<ABOUT_THIS_EXTENSION_ATTRIBUTE
-----------------------------------------------------------------------

	Written by:William Smith
	Technical Enablement Manager
	Jamf
	[email protected]
	https://gist.github.com/talkingmoose/4a2b613bf5273081459bc62c644193eb

	Description: A Jamf Pro extension attribute to return whether a user account
	(hidden or visible) in a list of user accounts exists on a computer.
	
	Originally posted: September 15, 2024

	Instructions:

	1. In Jamf Pro, click Settings > Computer management > Extension attributes
	   and create a new extension attribute:
	   
	   Display Name: "Existing user accounts"
	   Date Type: "String"
	   Inventory Display: "Extension Attributes"
	   Input Type: "Script"
	   
	2. Paste the entirety of this extension attribute script into the script
	   field.
	   
	3. Edit the list of management accounts below to include each user account
	   (one per line) you need to verify.

	Except where otherwise noted, this work is licensed under
	http://creativecommons.org/licenses/by/4.0/

	"In too many organizations, the people at the top have all the
	authority and none of the information, while the people on the
	front line have all the information and none of the authority."
	— Will Guidara
	
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ABOUT_THIS_EXTENSION_ATTRIBUTE

# Edit this list to include each user account (one per line) you need to verify
managementAccounts="jamfadmin
jamfmdm
lapsadmin
mdmadmin
talkingmoose"

# Verify whether each user account exists and is hidden or visible
while IFS= read anAccount
do
	# Read the details of an account
	accountDetails=$( /usr/bin/dscl . read "/Users/$anAccount" 2>/dev/null )
	
	# If an account exists, add its name to a list to report to Jamf Pro
	# and report whether it's hidden
	if [[ $accountDetails ]]; then
		isHidden=$( /usr/bin/awk '/IsHidden/ { print " (Hidden)" }' <<< "$accountDetails" )
		foundAccounts="$foundAccounts
$anAccount$isHidden"
	fi
done <<< "$managementAccounts"

# Return the verified accounts to Jamf Pro
echo "<result>$( /usr/bin/sed '/^$/d' <<< "$foundAccounts" )</result>"