Basic HTML version of Foils prepared April 16,1996

Foil 47 (?..) Constructs in Regular Expressions -III

From Perl5 and Advanced Perl4 Features Computational Science for Information Age Course CPS616 Material -- April 16,1996. by Geoffrey C. Fox
(?:regexp) means a simple grouping of regexp as a unit -- equivalent to (regexp) except it does not generate a $n reference
regexp1(?=regexp2) matches to regexp1 followed by regexp2 but regexp2 is not considered part of match
  • i.e. regexp1 in $MATCH, regexp2 in $POSTMATCH
regexp1(?!regexp2) matches to regexp1 NOT followed by regexp2
(?i) (?m) (?imsx) etc are equivalent to specifying modifiers i, m or i and m and s and x respectively

© Northeast Parallel Architectures Center, Syracuse University, npac@npac.syr.edu

If you have any comments about this server, send e-mail to webmaster@npac.syr.edu.

Page produced by wwwfoil on Sat Sep 6 1997