Re: Answer: How do I remove whitespace at the beginning or end of my string?

[repellent]

MRE_regx does not trim whitespace as expected:

$ perl -de 1

Loading DB routines from perl5db.pl version 1.3
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main::(-e:1):   1
  DB<1> $str = '  x  '; $str =~ s/^\s+((?:.+\S)?)\s+$/$1/s;

  DB<2> x $str
0  ' x'

[choroba]

Change it to

s/^\s+(\S?.*\S)\s+$/$1/s

[repellent]

use Test::More;

sub trim { my $s = $_[0]; $s =~ s/^\s+(\S?.*\S)\s+$/$1/s; $s }

is( trim('  '), '' );
is( trim('a  '), 'a' );
is( trim('  a'), 'a' );
is( trim('  a  '), 'a' );
is( trim('ab  '), 'ab' );
is( trim('  ab'), 'ab' );
is( trim('  ab  '), 'ab' );
is( trim('a bb c  '), 'a bb c' );
is( trim('  a bb c'), 'a bb c' );
is( trim('  a bb c  '), 'a bb c' );

done_testing();

__END__
not ok 1
#   Failed test at ./t.pl line 12.
#          got: '  '
#     expected: ''
not ok 2
#   Failed test at ./t.pl line 13.
#          got: 'a  '
#     expected: 'a'
not ok 3
#   Failed test at ./t.pl line 14.
#          got: '  a'
#     expected: 'a'
ok 4
not ok 5
#   Failed test at ./t.pl line 16.
#          got: 'ab  '
#     expected: 'ab'
not ok 6
#   Failed test at ./t.pl line 17.
#          got: '  ab'
#     expected: 'ab'
ok 7
not ok 8
#   Failed test at ./t.pl line 19.
#          got: 'a bb c  '
#     expected: 'a bb c'
not ok 9
#   Failed test at ./t.pl line 20.
#          got: '  a bb c'
#     expected: 'a bb c'
ok 10
1..10
# Looks like you failed 7 tests of 10.


The one I could find with best benchmark and passes tests is s/^\s*((?:.*\S)?)\s*$/$1/s;, which is essentially like MRE_regx with + replaced with * (perhaps trizen typo-ed?)