Something like this may do the job:

use strict;
use warnings;
use feature qw/ :5.10 /;

my @str = ("j    k l         foobar", "foobar", "jkl foobar", "1 2 3",
+ "jk l foobar", "foobar j k l", "foobar j kl", "           ", " ", "j
+ jk foobar", "j k jk foobar", "j k l");

my $rx = qr/^((?:\w(?:\s+|\z))*)(.*)/;

for my $str (@str){
  my ($i,$s) = $str =~ /$rx/;
  $i =~ s/\s+//g;
  say $i ? join " ",$i,$s : $s;
}

[download]

Outputs:

jkl foobar
foobar
jkl foobar
123
jk l foobar
foobar j k l
foobar j kl


j jk foobar
jk jk foobar
jkl

[download]

citromatik

In reply to Re: String manipulation by citromatik
in thread String manipulation by abhy

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