Re: regex question

["Mumia W.." <paduille.4061.mumia.w+nospam@earthlink.net>]

On 04/13/2008 07:00 AM, Alex Samad wrote:
> Yes I did (thanks twice), but my question which arose from this was why
> this did not work 
>
> perl -nle 'next if ( /^\s*;/);  print' sip.conf
>
> why do I need the length statement[?]
>
> perl -nle 'next if ( /^\s*;/);  print  if length $_ > 0' sip.conf
>
> [...]

First, this might be easier to understand:

perl -nle 'print unless /^\s*(#|$)/' sources.list
(Replace "#" with ";".)

Secondly, the "length" statement was needed for your earlier code
because /^\s*;/ won't match blank lines.

Take this code:
perl -nle 'next if ( /^\s*#/);  print  if length $_ > 0' sources.list

Simplify it a bit and use more regex's:
perl -nle 'next if (/^\s*#/ or /^\s*$/); print' sources.list

Integrate the regex'es into a single one:
perl -nle 'next if /^\s*(#|$)/; print' sources.list

Eliminate "next":
perl -nle 'print unless /^\s*(#|$)/' sources.list


HTH