That is almost correct, but it does remove a line break in the middle of the string it shouldn't

Who says it shouldn't?

The OP wanted whitespaces removed, that is what \s means, whitespaces (\n, \r, \t, \f, and " ") 

use YAPE::Regex::Explain;
print YAPE::Regex::Explain->new( qr/^\s+/ )->explain;
print YAPE::Regex::Explain->new( qr/\s+$/ )->explain;
__END__
The regular expression:

(?-imsx:^\s+)

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  ^                        the beginning of the string
----------------------------------------------------------------------
  \s+                      whitespace (\n, \r, \t, \f, and " ") (1 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------
The regular expression:

(?-imsx:\s+$)

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  \s+                      whitespace (\n, \r, \t, \f, and " ") (1 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

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In reply to Re^2: TRIM in Perl? by Anonymous Monk
in thread TRIM in Perl? by peacemaker1820

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