Thanks Vitaliy! That is just what I was looking for!

I suppose that underneath the code, deep down in Quote^%qcr, it may be doing the same as I'm doing, but it is unlikely to have any errors in it and it's not a wild assumption that it will do it in the most efficient way.

Alas, the few version 5 sites will have to live with my slower code

%SYS>w $zv
Cache for UNIX (IBM PowerPC/32-bit) 5.0.18 (Build 6103 + Adhoc 3626) Tue Mar 7 2006 11:55:33 EST
%SYS>W $zcvt(##CLASS(%Library.Utility).FormatString($lb("abc","DEF","",,"tesT",$lb(0))),"u")

W $ZCVT(##CLASS(%Library.Utility).FormatString($LB("abc","DEF","",,"tesT",$LB(0)
^
)),"u")
<CLASS DOES NOT EXIST>
%SYS>W $zcvt(##CLASS(%Utility).FormatString($lb("abc","DEF","",,"tesT",$lb(0))),"u")

W $ZCVT(##CLASS(%Utility).FormatString($LB("abc","DEF","",,"tesT",$LB(0))),"u")
^
<CLASS DOES NOT EXIST>

Thank you Erin. That's a nice try but $c(1) isn't guaranteed in a $LIST

s x=$lb(0) zzdump x

That's a really good idea. Doesn't quite get there because of nested lists.

Here is a bit more visual info on the problem:

>s x=$LB("test","for","searching unknown strings here is a very long piece with enough characters to get a lowercase alpha as a $list marker","items","in","lists",$lb("/subs","/values","nested list","did you see that ""w"" before the third piece?"))

>f i=1:1:$l(x) s c=$e(x,i) w:c?1c "$c("_$a(c)_")" w:c'?1c c

$c(6)$c(1)test$c(5)$c(1)forw$c(1)searching unknown strings here is a very long piece with enough characters to get a lowercase alpha as a $list marker$c(7)$c(1)items$c(4)$c(1)in$c(7)$c(1)listsM$c(1)$c(7)$c(1)/subs$c(9)$c(1)/values$c(13)$c(1)nested list.$c(1)did you see that "w" before the third piece?

It's those potential lowercase list separators that are forcing me to go the long way round with stepping through each piece. $ListToString may help speed the code up especially as I'm not really expecting deep nesting of lists.

Thanks Dmitry

I want to find any string in another string that could be a plain string, a $LIST, or a series of nested $LIST to any depth - basically an unkown structure. The string I'm searching in can be any size and the pieces can be any size. And I wan't to do a case insensitive search through a large amount of data and I want instant results. And I want to know the character positions of what was found. And I want the results in a human readable format. And just to make it hard, it has to run on everything from Caché version 5 upwards which means $LISTNEXT, $LISTVALID are not always available.

That would be fine if I was looking for the full element value as my search string. I'm looking for any occurance, full or part, in a lot of data.

 From the documentation:
  $LISTFIND searches the specified list for the first instance of the requested value. A match must be exact and consist of the full element value. Letter comparisons are case-sensitive. Numbers are compared in canonical form. If an exact match is found, $LISTFIND returns the position of the matching element. If value is not found, $LISTFIND returns a 0.

 // Suppose the string I'm  looking in is in
 S X=$LB("Stuart Strickland","Yaron Munz") // X could be anything
 // and I'm looking for "MUNZ"
 I $zcvt(X,"u")["MUNZ" Q 1  // I think this is quick but could cause a problem by converting lower case $LIST spacers to upper
 S sc=0 F i=1:1:$LL(X) S Y=$LG(X,i) I $zcvt(Y,"u")["MUNZ" s sc=1  // I think this is slow
 S sc=$LISTFIND(X,"MUNZ")         // I know this will not work
 S sc=$LISTFIND($zcvt(X),"MUNZ")  // I know this will not work and might even cause an error
 Q sc

I found a work around for it. Not perfect but it will do

S RTN=$ZU(96,9) // or $SYSTEM.Process.CallingRoutine() which is identical in this situation

I RTN="" F I=$ZU(41):-1:1 S RTN=$P($ZU(41,I),"^",3) I RTN'=$T(+0) Q:RTN'=""

That has the same problem

It appears to only work intermittently from "D zzpp".

If I ZLOAD another routine then go back and ZLOAD the first one, then it doesn't work.

But if I issue an argumentless ZSAVE  followed by "d zzpp" it works again.