Re: Does libtool need to escape plus signs in egrep expressions?

[Roumen Petrov]

Hello,

LRN wrote:
> While looking though ltmain source code i've stumbled upon this egrep 
> invocation:
> $EGREP ' (_head_[A-Za-z0-9_]+_[ad]l*|[A-Za-z0-9_]+_[ad]l*_iname)$'
> I've tried to see how it behaves on some import libraries that i have, and it
> turned out that i could never get it to detect the iname lines, unless i escape
> the plus sign.
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 .

> Note that the function that does this is only
> used in rather exotic corner-cases (old dlltool and/or ms dumpbin being in
> use), so it's plausible that it could have been broken since 2010, when it was
> added.


Regards,
Roumen Petrov