Functions and CALL Routines

Writing Perl Debug Output to the SAS Log

The DATA step provides debugging support with the CALL PRXDEBUG routine. CALL PRXDEBUG enables you to turn on and off Perl debug output messages that are sent to the SAS log.

The following example writes Perl debug output to the SAS log.

data _null_;

      /* CALL PRXDEBUG(1) turns on Perl debug output. */
   call prxdebug(1);
   putlog 'PRXPARSE: ';
   re = prxparse('/[bc]d(ef*g)+h[ij]k$/');
   putlog 'PRXMATCH: ';
   pos = prxmatch(re, 'abcdefg_gh_');

      /* CALL PRXDEBUG(0) turns off Perl debug output. */
   call prxdebug(0);
run;

SAS writes the following output to the log.

SAS Debugging Output

PRXPARSE: 
Compiling REx '[bc]d(ef*g)+h[ij]k$'
size 41 first at 1
rarest char g at 0
rarest char d at 0
   1: ANYOF[bc](10)
  10: EXACT <d>(12)
  12: CURLYX[0] {1,32767}(26)
  14:   OPEN1(16)
  16:     EXACT <e>(18)
  18:     STAR(21)
  19:       EXACT <f>(0)
  21:     EXACT <g>(23)
  23:   CLOSE1(25)
  25:   WHILEM[1/1](0)
  26: NOTHING(27)
  27: EXACT <h>(29)
  29: ANYOF[ij](38)
  38: EXACT <k>(40)
  40: EOL(41)
  41: END(0)
anchored 'de' at 1 floating 'gh' at 3..2147483647 (checking floating) stclass 
'ANYOF[bc]' minlen 7 

PRXMATCH: 
Guessing start of match, REx '[bc]d(ef*g)+h[ij]k$' against 'abcdefg_gh_'...
Did not find floating substr 'gh'...
Match rejected by optimizer

For a detailed explanation of Perl debug output, see CALL PRXDEBUG Routine.

Top of Page