Won't work for a single space at the beginning or end of the string. To fix: 
$string =~ s/(\S|^)\s(\S|$)/$1$2/g;

[download]
But the lookahead solution is preferable.
Caution: Contents may have been coded under pressure.

In reply to Re^5: Regular Expressions: Removing 'only' single spaces from a string by Roy Johnson
in thread Regular Expressions: Removing 'only' single spaces from a string by BioBoy

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