check frontmost BBEdit window with spellcheck http://shellcheck.net

shellcheck

tell application "BBEdit"
	if not (exists text document 1) then
		return
	end if
	
	if source language of text document 1 is not "UNIX Shell Script" then
		set thename to name of text document 1
		display dialog "Document '" & thename & "' does not seem to be a shell script!"
		return
	end if
	
	set theCode to text of text document 1
end tell

-- escape some crticial characters
set theCode to replace_chars(theCode, "\\", "\\\\")
set theCode to replace_chars(theCode, quote, "\"")
set theCode to replace_chars(theCode, "'", "\\'")
set theCode to replace_chars(theCode, "\n", "\\n")

tell application "Safari"
	open location "http://shellcheck.net"
	delay 1
	do JavaScript "document.getElementById('code').value = '" & theCode & "';" in document 1
	do JavaScript "transfer('#code', '#console')" in document 1
end tell

-- from the ever useful http://macosxautomation.com/applescript/sbrt/sbrt-06.html
on replace_chars(this_text, search_string, replacement_string)
	set AppleScript's text item delimiters to the search_string
	set the item_list to every text item of this_text
	set AppleScript's text item delimiters to the replacement_string
	set this_text to the item_list as string
	set AppleScript's text item delimiters to ""
	return this_text
end replace_chars

Note that Safari now needs to enable to 'Allow JavaScript from AppleEvents' in the Develop menu for this script to work.