Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight
 
PerlMonks  

Re^2: trim leading & trailing whitespace

by thinker (Parson)
on Mar 30, 2005 at 10:04 UTC ( #443390=note: print w/ replies, xml ) Need Help??


in reply to Re: trim leading & trailing whitespace
in thread trim leading & trailing whitespace

Hi bart

In the example I gave above,

 s/^\s*(.*?)\s*$/$1/gm

the combination of the \m modifier, and the line anchors ^ and $ will ensure the newlines are left alone

cheers

thinker


Comment on Re^2: trim leading & trailing whitespace
Select or Download Code
Re^3: trim leading & trailing whitespace
by bart (Canon) on Mar 30, 2005 at 10:08 UTC
    $_ = " no \n \n \n they \n \n won't \n\n\n"; s/^\s*(.*?)\s*$/$1/gm; print;
    Result:
    no
    they
    won't
    

    All blank lines are gone.

      Hi bart,

      I see what you mean now. I thought you were suggesting it would remove the newline characters, not just the blank lines. Your way is more correct.

      cheers

      thinker

      How about this:

      $_ = " yes \n \n \n they \n \n will \n\n\n"; s/^\s*?(?:\b(.*?)\s*?)?(\n)?$/$1$2/gm; print; __END__ % perl 443391.pl yes they will

      the lowliest monk

        Danger, don't use \b if you want to detect the edges between spaces an nonspaces. It won't work for nonspace+nonword characters, like quotes and punctuation.

        Perhaps replace the \b(.*?) with (\S.*?).

        Still, you're not running this with warnings enabled, are you? Both $1 and $2 are optional, so both can be undef, but you use their value regardless. This runs without warnings:

        s/^\s*?((?:\S.*?)?)\s*?(\n?)$/$1$2/gm;

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://443390]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others studying the Monastery: (7)
As of 2015-07-02 05:04 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (28 votes), past polls