Checking if a user account exists?

Hi Cassie

Does it have to be a shell script?

--begin script
tell application "System Events" to name of every user contains "test"
if the result is false then...
-- end script

Hope it helps.

H

There are two flaws in your script.

First of all, if you man grep you'll eventually find that:

Normally, exit status is 0 if selected lines are found and 1 otherwise.

What you're seeing is that grep is returning exit status 1 (no lines found) and AppleScript interprets any exit status other than 0 as an error from the shell command.

In theory, grep's '-q' switch should change this behavior, but it doesn't appear to, so the alternative is to use a try block to catch the error:

set isFound to 0
try
set isFound to do shell script "grep -i -c \"test\" /etc/passwd"
end try
if isFound ≠ 0 then
...
end if

However, the second error is that this is likely to return 0 anyway because user accounts are not stored in /etc/passwd as they are on most other Unix systems. Even if they were there, your script would match any user with 'test' in their account entry, including a 'real name' of 'Testing account'.

If your machine is standalone, you're better off querying NetInfo for the username. Either:

do shell script "nicl . -list /users | grep -i \"test$\""

(with the same caveats as above when dealing with a non-0 exit status) or, even better, query the user account directly:

set userAccount to "Invalid User"
try
set userAccount to do shell script "nicl . -read /users/test"
end try
if userAccount ≠ "Invalid User" then
-- user exists
end if

This works for me:

(do shell script "nicl . -list /users") contains "test"
--> if a user is "test"
if result is true then...

but

tell application "System Events" to (name of every user) contains "test"
--> true if a user is "test"
if result is true then....

is faster.

but the tell application "system events" didn't work
for me? 😟

Are you an Admin user when you run it?