how to modify PERL Regular Expression in my sample code

[blueskyxyz]

Hi guys, could you help  to modify code since I'm not familar with PRX.

I want to extract the words including lower case letters, upper case letters and digits,(a-z,A-Z,0-9), and the length word is 8.

\w

data a;
	length string $200;
	string='Befor??e Bexfore1 Beforexx  xxxxxxxx  nightmare  or On the End,..ed 1234(678 of abc abc12345  1234567_   1 high';
run;

data a1;
 	length s1 $8 ;
	set a;
	do i=1 to countw(string,' ');
	  temp=scan(string,i,' ');
	  if prxmatch("/\w{8}?/",temp) and not index(temp,"_")  then do;
		 s1=temp;
		 output;
	  end;
	end;
run;

how to modify the PRX to delete the word "nightmare" whose length is over 8? offer more than one method of PRX?

[PGStats · Accepted solution]

prxNext routine allows you to scan a string efficiently. Instead of using \w to mean a word character (including an underscore) and then testing for the presence of an underscore, be explicit and specify [a-zA-Z0-9]

data a1;
prxId = prxparse("/\b[a-zA-Z0-9]{8}\b/o");
set a;
start = 1; stop = -1;
call prxnext(prxID, start, stop, string, position, length);
  do while (position > 0);
     found = substr(string, position, length);
     output;
     call prxnext(prxID, start, stop, string, position, length);
  end;
keep string found;
run;

[blueskyxyz]

hi PG, thank you very much,  \b match word boundary