As a slightly unweildy one-liner:

perl 
-ne"if(/processed/){ print($last),undef($last) if $last; print;}else{$
+last=$_}" 
junk.dat
**start xyz
File1 processed
File2 processed
**start wert
File3 processed
File4 processed
[download]

Thanks for your help. I am kinda new to perl. Can you be a bit more specific on the syntax please?

C:\test>type junk86.pl
#! perl -sw
use strict;

my $last;
while( <> ) {
    if( /processed/ ){
        if( $last ) {
            print( $last );
            undef( $last )
        }
        print;
    }
    else{
        $last = $_;
    }
}

C:\test>type junk.dat
**start abc
**start adl
**start xyz
File1 processed
File2 processed
**start zxcv
**start wert
File3 processed
File4 processed

C:\test>junk86 junk.dat >junk.new

C:\test>type junk.new
**start xyz
File1 processed
File2 processed
**start wert
File3 processed
File4 processed
[download]

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

Here’s the basic strategy...

Initialize a variable (or as the case may be, an array) to catch the last (the last n...) line(s) that have been seen.   When you realize that you are now looking at a matching line, the variable (or array) contains the last line(s) that you saw before that one.

If the variable is undef (see the function, “defined()”), or if the array is empty, then there were no lines prior to the matching line.