use strict;
use warnings;

my $text = q{
I need to extract the first several words from a paragraph of text contained in a $var, 
so as to get the longest extract that's less than or equal to 200 characters. 
My brute-force-and-ignorance method is: blah some more text here etc etc
};

my $chunk;

($chunk) = $text =~ /^(.{1,200})(?<!\s)(?!\w)/;

printf "[%d] %s\n", length($chunk), $chunk;

$chunk = $text;

$chunk =~ s/^(.{200}).*$/$1/;
$chunk =~ s/^(.*)\s+\w*$/$1/;

printf "[%d] %s\n", length($chunk), $chunk;

$chunk = "";
$text =~ s/^\s+//;

foreach (split /\s+/, $text) {
	if (length($chunk) + length($_) <= 200) {
		$chunk .= $_ . " ";	
	} else {
		last;
	}
}

chop $chunk;
printf "[%d] %s\n", length($chunk), $chunk;