read from file a selected chunk of information?

Scripting Forums AppleScript | Mac OS X
#1

Hello:

I’m pretty new at this, but am trying to read a text file and extract a specific piece of information from the file (say, in the example below, the information on the line prefixed by SaveRGBImagesPrefix and ending at the return).

I know how to open a file, access it, and close it, but haven’t done much with reading and using delimiters (I’m guessing that’s what’s called for here…).

Is there a good generalized routine for reading a text file until a given phrase, and ending with a return?

Here’s an example of the contents of the text file:

Thanks in advance for your help.

– jpburns

#2

If your text files aren’t large, this might work. It reads the entire file and then looks for the targeted text. If your files are large, you might need a script that reads the file in chunks. There is probably a more elegant way to do this but I haven’t had enough coffee to think about it. :wink:

set foo to read file "path:to:your:file"
set targetText to "SaveRGBImagesPrefix"
set extractedProperty to ""
set foundIt to "Target text not found."

set oldDelims to AppleScript's text item delimiters
try
	set AppleScript's text item delimiters to {ASCII character 13}
	set bar to text items of foo
	repeat with thisItem in bar
		if thisItem contains targetText then
			set foundIt to thisItem
			exit repeat
		end if
	end repeat
	set AppleScript's text item delimiters to oldDelims
on error
	set AppleScript's text item delimiters to oldDelims
end try

display dialog foundIt -- for demo only

repeat with thisWord in words of foundIt
	if contents of thisWord is not targetText then
		set extractedProperty to extractedProperty & thisWord & ":"
	end if
end repeat

set extractedProperty to characters 1 thru -2 of extractedProperty as text

display dialog extractedProperty -- for demo only
#3

Thanks so much. This is just great.

I’ve already started messing with it. I’ve made the file user selectable by changing the start to:


set foo to read file ((choose file with prompt "Pick a scene file") as string)
...

I hope to generalize this even further and use it to do all of my searches (by making it into a handler).

Thanks again.

jpburns

#4

A much quicker way would be to:

 set bar to read file "path:to:your:file" using delimiters {return}

In this way the file is automatically broken into a line-based list as it’s read. In the original code you have two copies of the entire file in memory - the original ‘pure’ copy, and the line-delimited version.

#5

Of course you are correct. When I tried this earlier, it didn’t work, and then I got distracted. I later discovered that the test text file, generated with BBEdit, contained unix line breaks. Thanks for the heads up. :slight_smile: