I thought there must be a quick solution, but I could only think of this:

#!/usr/bin/perl -w
use strict;
my $string = "a  'b c d'  e  f  'g h'";

my $tmp='';
my @result = ();
for (split /\s+/, $string) {
    if (/^'/) {
        $tmp = $_; next;
    }
    elsif (/'$/) {
        push @result, $tmp." $_"; $tmp=''; next;
    }
    elsif($tmp) {
        $tmp.=" $_";
    }
    else {
        push @result,$_;
    }
}
print join "\n", @result;
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Of course, you could use the DBD::CSV module, setting the record delimiter to 'space' and the text quantifier to 'single quote' (spelled for clarity, not for actual use :)...

But my guess is that would be slower than a purpose designed parser for this very specific case.

.02

cLive ;-)