How to re-format a .txt list in Applescript

Question

I have a file (list.txt) with a list that contains thousands of lines that look like this:

carpet-redandblue
shelf-brown
metaldesk-none

Is there a script I can use to remove everything after the "-", including the "-" as well?

This is what I have so far:

set theFile to "/Users/home/Desktop/list.txt"
if theFile contains "-" then
    set eol to "-"
else
    set eol to "-"
end if

But doesn't seem to be working. Do I have to define an output file with a filename and path?

Answer 1

This should do what you need, at least as I understand it. The script reads the text file into a variable. It then breaks the text into paragraphs (or lines) and splits each line at the first dash. It then converts each line back into paragraphs of a text. Finally, it writes the resulting text to a text file. If you prefer to use the resulting text in some other way, it is stored in the prunedText variable.

use scripting additions

(*
set rawText to "carpet-redandblue
shelf-brown
metaldesk-none"
*)
set rawText to read file ((path to desktop as text) & "list.txt")

set AppleScript's text item delimiters to "-"
set paraText to paragraphs of rawText
--> {"carpet-redandblue", "shelf-brown", "metaldesk-none"}

set wordPara to {}
repeat with eachLine in paraText
    set end of wordPara to first text item of eachLine
end repeat
--> {"carpet", "shelf", "metaldesk"}

set AppleScript's text item delimiters to linefeed
set prunedText to wordPara as text
(*
 "carpet
shelf
metaldesk"
*)

-- optionally
tell application "Finder"
    set nl to ((path to desktop as text) & "newList.txt") as «class furl»
end tell

close access (open for access nl)
write prunedText to nl as text