Perl: function to trim string leading and trailing whitespace

Question

Is there a built-in function to trim leading and trailing whitespace such that trim(\" hello world \") eq \"hello world\"?

Answer 1

This is available in String::Util with the trim method:

^{Editor's note: String::Util is not a core module, but you can install it from CPAN with [sudo] cpan String::Util.}

use String::Util 'trim';
my $str = "  hello  ";
$str = trim($str);
print "string is now: '$str'\n";

prints:

string is now 'hello'

However it is easy enough to do yourself:

$str =~ s/^\s+//;
$str =~ s/\s+$//;

Answer 2

According to this perlmonk's thread:

$string =~ s/^\s+|\s+$//g;

Answer 3

No, but you can use the s/// substitution operator and the \s whitespace assertion to get the same result.

Answer 4

I also use a positive lookahead to trim repeating spaces inside the text:

s/^\s+|\s(?=\s)|\s+$//g