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