lineoffset - In Reverse
revdev at pdslabs.net
Tue Nov 17 12:30:32 CST 2009
Here's an approach that might give you what you need. It assumes the
file is already in a "vFile" variable, and that the contents of vFile
won't be rewritten - in other words it's disposable:
-- find an unused character to use as a line delimiter
put empty into tMarkerChar
repeat with x = 255 down to 1 -- I didn't include 0 - it might cause
problems in this context
if numToChar(x) is not in vFile then
put numToChar(x) into tMarkerChar
-- exit if every ASCII char is used in the file
if tMarkerChar = empty then
answer "Can't do it!"
exit to top
-- get the data chunk in question
replace "------------..." with tMarkerChar in vFile
set the lineDelimiter to tMarkerChar
put line -2 of vFile into tFoundSegment
set the lineDelimiter to CR
So now you've isolated your data chunk. I may have missed something, but
this approach is simple and should work.
Hope this helps -
Len Morgan wrote:
> I'm trying to parse a file, who's format I have no control over. I
> have found the pattern that I need but in order to make it work
> (easily) I need the equivalent of lineoffset to work from the end mark
> (which I can reliably find) and the start of that section which is a
> variable number of lines above the end mark.
> The start of a section is a line by itself with "------------..." but
> this same line is also used to mark off other sections that I don't
> need. So, what I need to do is:
> 1) find the line offset to the next end-of-section marker
> 2) find the line offset from #1 BACKWARDS to the first line that
> starts with "------------..."
> Is there such a function? I can always roll my own and just read
> lines backwards from #1 above until I find the start mark but why
> reinvent the wheel if such a function is already in revTalk.
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