A little regex help please ...

[Justin Willmert]

Brian D. McGrew wrote:
> Yeah, you did understand but I should have been more clear because my release tress go way back and don't all begin with 5.  We go clear back to 3; so it could be
>
> 3.0
> 3.1
> 3.1-*
> 3.1_*
> 3.2
> 3.2-*
> ....
> 4.5
> 4.5-*
> 4.5_*
> ...
> 5.0
> 5.0-*
> 5.0_*
>
> There is about 300 directories I'm walking through here.
>   
I know you got another reply using other utilities, but since you asked 
for a regex command, I though this might be interesting. The sort -u is 
just there to take out any repeated numbers and then sort them 
alphanumerically.

ls | perl -n -e 'print "$1\n" if ( /([0-9.]+).*/ );' | sort -u

If you want to include the dashes and underscores in the listing, just 
change the regex to:

/([0-9.]+[-_]?).*/

Justin Willmert