perl -Mre=debug -le"print $1 while q!bbbbabcabc! =~ /\G(\w\w\w)*?abc/g" perl -Mre=debug -le"print $1 while q!bbbbabcabc! =~ /(\w\w\w)*?abc/g" ##

##

$ perl -Mre=debug -le"print $1 while q!bbbbabcabc! =~ /\G(\w\w\w)*?abc/g"
Compiling REx "\G(\w\w\w)*?abc"
synthetic stclass "ANYOF[0-9A-Z_a-z][{unicode_all}]".
Final program:
   1: GPOS (2)
   2: MINMOD (3)
   3: CURLYM[1] {0,32767} (14)
   7:   ALNUM (8)
   8:   ALNUM (9)
   9:   ALNUM (12)
  12:   SUCCEED (0)
  13: NOTHING (14)
  14: EXACT  (16)
  16: END (0)
floating "abc" at 0..2147483647 (checking floating) stclass ANYOF[0-9A-Z_a-z][{unicode_all}] anchored(GPOS) GPOS:0 minlen 3
Matching REx "\G(\w\w\w)*?abc" against "bbbbabcabc"
   0 <>          |  1:GPOS(2)
   0 <>          |  2:MINMOD(3)
   0 <>          |  3:CURLYM[1] {0,32767}(14)
                                  CURLYM trying tail with matches=0...
   0 <>          |  7:  ALNUM(8)
   1           |  8:  ALNUM(9)
   2           |  9:  ALNUM(12)
   3           | 12:  SUCCEED(0)
                                    subpattern success...
                                  CURLYM now matched 1 times, len=3...
                                  CURLYM trying tail with matches=1...
   3           |  7:  ALNUM(8)
   4           |  8:  ALNUM(9)
   5           |  9:  ALNUM(12)
   6           | 12:  SUCCEED(0)
                                    subpattern success...
                                  CURLYM now matched 2 times, len=3...
                                  CURLYM trying tail with matches=2...
   6           |  7:  ALNUM(8)
   7           |  8:  ALNUM(9)
   8           |  9:  ALNUM(12)
   9           | 12:  SUCCEED(0)
                                    subpattern success...
                                  CURLYM now matched 3 times, len=3...
                                  CURLYM trying tail with matches=3...
   9           |  7:  ALNUM(8)
  10  <>         |  8:  ALNUM(9)
                                    failed...
                                  failed...
Match failed
Freeing REx: "\G(\w\w\w)*?abc"

##

## $ perl -Mre=debug -le"print $1 while q!bbbbabcabc! =~ /(\w\w\w)*?abc/g" Compiling REx "(\w\w\w)*?abc" synthetic stclass "ANYOF[0-9A-Z_a-z][{unicode_all}]". Final program: 1: MINMOD (2) 2: CURLYM[1] {0,32767} (13) 6: ALNUM (7) 7: ALNUM (8) 8: ALNUM (11) 11: SUCCEED (0) 12: NOTHING (13) 13: EXACT (15) 15: END (0) floating "abc" at 0..2147483647 (checking floating) stclass ANYOF[0-9A-Z_a-z][{unicode_all}] minlen 3 Guessing start of match in sv for REx "(\w\w\w)*?abc" against "bbbbabcabc" Found floating substr "abc" at offset 4... start_shift: 0 check_at: 4 s: 0 endpos: 5 Does not contradict STCLASS... Guessed: match at offset 0 Matching REx "(\w\w\w)*?abc" against "bbbbabcabc" Matching stclass ANYOF[0-9A-Z_a-z][{unicode_all}] against "bbbbabca" (8 chars) 0 <> | 1:MINMOD(2) 0 <> | 2:CURLYM[1] {0,32767}(13) CURLYM trying tail with matches=0... 0 <> | 6: ALNUM(7) 1 | 7: ALNUM(8) 2 | 8: ALNUM(11) 3 | 11: SUCCEED(0) subpattern success... CURLYM now matched 1 times, len=3... CURLYM trying tail with matches=1... 3 | 6: ALNUM(7) 4 | 7: ALNUM(8) 5 | 8: ALNUM(11) 6 | 11: SUCCEED(0) subpattern success... CURLYM now matched 2 times, len=3... CURLYM trying tail with matches=2... 6 | 6: ALNUM(7) 7 | 7: ALNUM(8) 8 | 8: ALNUM(11) 9 | 11: SUCCEED(0) subpattern success... CURLYM now matched 3 times, len=3... CURLYM trying tail with matches=3... 9 | 6: ALNUM(7) 10 <> | 7: ALNUM(8) failed... failed... 1 | 1:MINMOD(2) 1 | 2:CURLYM[1] {0,32767}(13) CURLYM trying tail with matches=0... 1 | 6: ALNUM(7) 2 | 7: ALNUM(8) 3 | 8: ALNUM(11) 4 | 11: SUCCEED(0) subpattern success... CURLYM now matched 1 times, len=3... CURLYM trying tail with matches=1... 4 | 13: EXACT (15) 7 | 15: END(0) Match successful! bbb Guessing start of match in sv for REx "(\w\w\w)*?abc" against "abc" Found floating substr "abc" at offset 0... start_shift: 0 check_at: 7 s: 7 endpos: 8 Does not contradict STCLASS... Guessed: match at offset 0 Matching REx "(\w\w\w)*?abc" against "abc" Matching stclass ANYOF[0-9A-Z_a-z][{unicode_all}] against "a" (1 chars) 7 | 1:MINMOD(2) 7 | 2:CURLYM[1] {0,32767}(13) CURLYM trying tail with matches=0... 7 | 13: EXACT (15) 10 <> | 15: END(0) Match successful! Freeing REx: "(\w\w\w)*?abc"