Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

Re^4: removing the white spaces

by japhy (Canon)
on Apr 13, 2006 at 14:27 UTC ( #543097=note: print w/ replies, xml ) Need Help??


in reply to Re^3: removing the white spaces
in thread removing the white spaces

I've mentioned this before, I'll explain it again.

The substitution s/^\s+// is simple and direct: replace a chunk of whitespace at the beginning of the string with nothing. The substitution s/\s+$// is simple and almost as direct: replace a chunk of whitespace followed by the end of the string with nothin. Sadly, it's not as "perfect" as the first one -- it matches each chunk of whitespace and examines it to see if it's at the end of the string or not. Oh well.

When you say s/^\s+|\s+$//g, perl's regex engine gets stupid. Real dumb. It tries BOTH branches of that regex at every location in the string. EVERY LOCATION! EVEN WHERE THERE AREN'T SPACES! See for yourself with perl -mre=debug -e '$_ = " a  b   c    "; s/^\s+|\s+$//g' It's upsetting!

So do it with two regexes. Give peace a chance.


Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart


Comment on Re^4: removing the white spaces
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://543097]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (14)
As of 2014-07-23 21:13 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (152 votes), past polls