use strict;
use warnings;

my @strs = (
    "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 @sanitisedNames = ();

for my $str (@strs) {
    my $oStr = $str;

    $str =~ s/\G([a-z])\s+(?!\w{2})/$1/gi;
    $str =~ s/\s+/ /g;

    push @sanitisedNames, [$oStr, $str];

}

printf "%-25s >%s<\n", @$_ for (@sanitisedNames);