Nagging space after splitting

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Nagging space after splitting by Zaxo (Archbishop) on May 31, 2005 at 06:16 UTC
The presence of initial spaces forces the empty string as the first element. That effect is suppressed for trailing match, but the initial match is regarded an a separator. The magical split trims leading and trailing whitespace, so is probably what you want: `$ perl -MData::Dumper -e ' > $str = " STRING "; > @ar = split(" ", $str); > print Dumper \@ar;' $VAR1 = [ 'STRING' ]; $` [download] After Compline, Zaxo	[reply] [d/l]
Re: Nagging space after splitting by ivancho (Hermit) on May 31, 2005 at 06:18 UTC
from `perldoc -f split` `As a special case, specifying a PATTERN of space (' ') will split on white space just as "split" with no arguments does. Thus, "split(' ')" can be used to emulate awk's default behavior, whereas "split(/ /)" will give you as many null initial fields as there are leading spaces. A "split" on "/\s+/" is like a "split(' ')" except that any leading whitespace produces a null first field. A "split" with no arguments really does a "split(' ', $_)" internally.` [download]	[reply] [d/l] [select]
Re: Nagging space after splitting by dbwiz (Curate) on May 31, 2005 at 06:57 UTC
There is a good explanation of your problem in Re: Tutorial suggestion: split and join.	[reply]
Re: Nagging space after splitting by tlm (Prior) on May 31, 2005 at 06:19 UTC
Your regex is fine. `split` returns the stuff around the regex; in this case, the resulting first element is the empty string before the regex. But you can obtain the desired behavior by using the special first argument `' '` for `split`: `my @ar = split( ' ', $str );` [download] the lowliest monk	[reply] [d/l]
Re: Nagging space after splitting by ikegami (Patriarch) on May 31, 2005 at 07:02 UTC
If you were splitting on something other than whitespace (and thus couldn't use `" "` for the pattern), you could do: `@ar = split(/$pattern/, $str); shift(@ar);` [download] or `$str =~ s/^$pattern//; @ar = split(/$pattern/, $str);` [download] If you knew the number of fields, you could also use: `@ar = (split(/$pattern/, $str))[1..$n-1];` [download]	[reply] [d/l] [select]
Re: Nagging space after splitting by tphyahoo (Vicar) on May 31, 2005 at 08:00 UTC
Look at it another way. `perl -MData::Dumper -e ' $str = ",STRING,"; @ar = split(/,/,$str); print Dumper \@ar;'` [download] should also give you an empty first field, right? Maybe that demo helps make this behavior more understandable.	[reply] [d/l]
Re: Nagging space after splitting by tchatzi (Acolyte) on May 31, 2005 at 07:41 UTC
In your case it will work like this `# perl -MData::Dumper -e ' > $str = " STRING "; > $str =~ s/\s//g; > push(@ar,$str); > print Dumper \@ar;'` [download] You will get `$VAR1 = [ 'STRING' ];` [download] Is this what you want? But if you want to use split then use it as Zaxo told you ``The wise man doesn't give the right answers, he poses the right questions.'' TIMTOWTDI	[reply] [d/l] [select]