What I use a *LOT* is

on tidreplace(sometext, intext, outtext)
	tell application "Finder"
		set tid to AppleScript's text item delimiters
		set AppleScript's text item delimiters to intext
		set sometext to every text item of sometext
		set AppleScript's text item delimiters to outtext
		set sometext to sometext as text
		set AppleScript's text item delimiters to tid
	end tell
	return sometext
end tidreplace

I have it in a library even.  It only does case sensitive replaces so  
its not perfect.

Another option you may want to consider is using sed through do shell  
script.


On Oct 20, 2006, at 4:20 PM, Eric Schult wrote:

> I've been using ACME Script Widgets' "ACME Replace" command for so  
> long I=
>
> barely remember how to search and replace strings within strings in  
> vanil=
> la
> AS. However, I find myself needing to do that, because my ACME Replace
> commands are hanging in some of my newer scripts in OS 10.3.8.  
> (They neve=
> r
> error out; the script just never finishes running, and then script  
> editor=
>
> crashes.)
>
> I've just written a vanilla AS variation that works, but I'm  
> worried I'll=
>
> bump into errors when running this script on a very long string. Maybe
> that's not an issue anymore, but I recall in earlier versions of  
> the Mac =
> OS
> and AS having to bite off the task in blocks. Is that still true,  
> and wha=
> t
> is the limitation?
>
> If anybody has a variation on the following  script that'll do the  
> same
> thing and handle large blocks of text in a more efficient manner,  
> I'd rea=
> lly
> appreciate seeing an example of it.
>
> Thanx!
>
> WES
>
>
> set myTextBlock to "This string contains more than one instance of  
> the wo=
> rd
> 'foo', and 'foo' is the string I want to substitute with some other  
> word
> other than 'foo'."
> set subString to "not_foo"
>
> set AppleScript's text item delimiters to "foo"
> set stringList to text items in myTextBlock
> set AppleScript's text item delimiters to ""
>
> set newString to ""
> set stringCount to count of items in stringList
> if stringCount is greater than 1 then
>  repeat with i from 1 to count of items in stringList
>   set thisString to item i in stringList
>    if i is not stringCount then
>     set newString to newString &  ¬
>      (thisString & subString) as string
>    else
>     set newString to newString & thisString
>    end if
>  end repeat
> end if
>
> return newString
>