How to properly pass nested lists from Applescript to Bash - bash

Question

I'm working on a project that involves using Applescript to make a list of open URLs within the users Google Chrome Browser, in order to save them for when I eventually want to re-open Chrome. Finding that I needed to have a way to determine which tabs were present in which windows, I decided to try and make a nested list in Applescript, in which each window is it's own sublist of tab URLs, and then return it in the variable declared before the subshell.
The way I'm doing this is via the following code
tabs=$(/usr/bin/osascript << EOT
tell application "Google Chrome"
# save a variable to the number of windows open
set windowCount to number of windows
set myWindows to {}
repeat with x from 1 to windowCount
# count the tabs in the window we are iterated upon
set tabcount to number of tabs in window x
# this list will hold the URLs, delimited by commas
set myURLs to {}
# secondary loop, this time iterating tabs
repeat with y from 1 to tabcount
# grab URL from current tab
set tabURL to URL of tab y of window x
# append URL to end of list
copy tabURL to the end of myURLs
end repeat
# this means our end result will be a list of lists
# containing the URLs of all the tabs of all the windows
copy myURLs to the end of myWindows
end repeat
return myWindows
end tell
EOT)
The issue I'm running into is that, although Applescript is building the nested list properly, i.e.
{{"https://stackoverflow.com/questions/ask"}, {"https://twitter.com", "https://facebook.com"}}
Bash seems to flatten the list when I reference $tabs later into something like
https://stackoverflow.com/questions/ask, https://twitter.com, https://facebook.com
which leads me to believe Applescript and Bash aren't getting along when passing complex variables. Is this the case and is Bash not able to read multi-dimensional lists from Applescript? Or am I simply programming this incorrectly?
Thank you!

Answer 1

Here's a basic, barebones script that contains two handlers: storeURLs() and restoreURLs().
storeURLs() retrieves a nested list of currently-open Chrome tabs (grouped by window) and writes their URLs out to file. restoreURLs() reads this file and opens the URLs in Chrome, restoring the arrangement of tabs and windows.
Running the script in its current form will store the list of URLs in the file ~/.chrometabs. To get the script to restore the saved URLs, comment out the first occurrence of "storeURLs()" (line 6) by prepending it with two hyphens (--) or a hash (#); and uncomment the line below that, by deleting the two hyphens before "restoreURLs()".
property home : system attribute "HOME"
property file : home & "/.chrometabs" --> /Users/%YOU%/.chrometabs
on run
storeURLs()
--restoreURLs()
end run
on storeURLs()
close access (open for access my file)
tell application id "com.google.chrome" to set ¬
URLs to the URL of every tab in every window
write the URLs to my file
return the URLs
end storeURLs
to restoreURLs()
close access (open for access my file)
if (get eof of my file) = 0 then return false
set URLs to read my file as list
tell application id "com.google.chrome"
repeat with URLgroup in the reverse of URLs
tell (make new window)
set the active tab's URL to the URLgroup's 1st item
repeat with |URL| in the rest of the URLgroup
make new tab with properties {URL:|URL|}
end repeat
end tell
end repeat
activate
end tell
return the URLs
end restoreURLs
The script doesn't contain anything more than the most basic error-prevention, and as such, will benefit from additional error-handling. It was written and tested using AppleScript version 2.5 in macOS 10.12.6. The only potential problem I anticipate in more recent versions of macOS (Mojave, Catalina) would be security bollocks that could prevent the script creating and/or writing to the file path ~/.chrometabs, either due to its location, or due to the leading "." in the file name which denotes an invisible file in macOS.