Re: Riddle me this: grep / regx experts

[Patrick O'Callaghan]

On Fri, 2018-02-02 at 12:32 -0500, R. G. Newbury wrote:
>  > Thanks to all for the quick responses. I *tried* to RTFM but
> that was 
>  
>  not clear, even on a re-read.  I took [0-9]* as multiple instances of 
>  [0-9] but NOT zero instances.. 
From 'man grep':

Repetition
       A regular expression may be followed by one of several repetition operators:
       ?      The preceding item is optional and matched at most once.
       *      The preceding item will be matched zero or more times.
       +      The preceding item will be matched one or more times.
       {n}    The preceding item is matched exactly n times.
       {n,}   The preceding item is matched n or more times.
       {,m}   The preceding item is matched at most m times.  This is a GNU extension.
       {n,m}  The preceding item is matched at least n times, but not more than m times.

poc