Check shell script status

Question

The following question is related to the same application I am developing in the thread named "Open something on first launch?", if that may help you answer it.
How exactly do I check to see if hidden files are being displayed or not?
This:
set shellcheck to do shell script "defaults read com.apple.Finder AppleShowAllFiles"
if the result returned in shellcheck = FALSE then
display dialog "FALSE"
else if the result returned in shellcheck = TRUE then
display dialog "TRUE"
end if
or this:
set shellcheck to do shell script "defaults read com.apple.Finder AppleShowAllFiles"
if shellcheck = false then
display dialog "FALSE"
else if shellcheck = true then
display dialog "TRUE"
end if
doesn't seem to work...

Answer 1

The first thing to realize is that if the defaults parameter doesn't exist, the script will return an error. Therefore your code needs to include a try/end try block to catch that error.
Secondly, if the key/value does exist, defaults will return '1' if it's true, or '0' if it's false.
Therefore, your script should look more like:
try
  set shellcheck to do shell script "defaults read com.apple.Finder AppleShowAllFiles"
  if shellcheck = "0" then
    display dialog "FALSE"
  else if shellcheck = "1" then
    display dialog "TRUE"
  end if
on error
  display dialog "Preference value does not exist"
end try