Re: Does libtool need to escape plus signs in egrep expressions?
Bob Friesenhahn <[email protected]>
| Newsgroups | gmane.comp.gnu.libtool.general |
|---|---|
| Message-ID | <[email protected]> |
On Thu, 28 Jun 2018, Roumen Petrov wrote: > May be I misunderstand issue. > > $ echo ' _head_ABC_a' | egrep ' _head_[A-Za-z0-9_]+_[ad]l*$' > _head_ABC_a > > $ echo ' _head_ABC_al' | egrep ' _head_[A-Za-z0-9_]+_[ad]l*$' > _head_ABC_al > > but: > $ echo ' _head__al' | egrep ' _head_[A-Za-z0-9_]+_[ad]l*$' > $ echo ' __head_ABC_al' | egrep ' _head_[A-Za-z0-9_]+_[ad]l*$' > $ echo ' _head_ABC_zl' | egrep ' _head_[A-Za-z0-9_]+_[ad]l*$' > > > >> Are you sure this actually works? > I'm not expert in regular expressions but according above tests "plus" in RE > works - see case _head__al . It should match a run of alpha-numeric characters including underscores. However, I do see that the expression includes a match of literal underscore and then there is a literal underscore so there might be something going on with that. Greedy matching would likely absorb a final underscore so it might not be possible to match on that final literal underscore. This might expose differences in behaviors between egreps. Bob -- Bob Friesenhahn [email protected], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ https://lists.gnu.org/mailman/listinfo/libtool