Text::Trim(3)

NAME
Text::Trim - remove leading and/or trailing whitespace from strings

VERSION
version 1.04

SYNOPSIS
    use Text::Trim;

    $text = "\timportant data\n";
    $data = trim $text;
    # now $data contains "important data" and $text is unchanged

    # or:
    trim $text; # work in-place, $text now contains "important data"

    @lines = <STDIN>;
    rtrim @lines; # remove trailing whitespace from all lines

    # Alternatively:
    @lines = rtrim <STDIN>;

    # Or even:
    while (<STDIN>) {
        trim; # Change $_ in place
        # ...
    }

DESCRIPTION
This module provides functions for removing leading and/or trailing whitespace from strings. It is basically a wrapper around some simple regexes with a flexible context-based interface.

EXPORTS
All functions are exported by default.

CONTEXT HANDLING

  void context
Functions called in void context change their arguments in-place

    trim(@strings); # All strings in @strings are trimmed in-place

    ltrim($text);   # remove leading whitespace on $text

    rtrim;          # remove trailing whitespace on $_

No changes are made to arguments in non-void contexts.

  list context
Values passed in are changed and returned without affecting the originals.

    @result = trim(@strings);    # @strings is unchanged

    @result = rtrim;             # @result contains rtrimmed $_

    ($result) = ltrim(@strings); # like $result = ltrim($strings[0]);

  scalar context
As list context but multiple arguments are stringified before being returned. Single arguments are unaffected. This means that under these circumstances, the value of $" ($LIST_SEPARATOR) is used to join the values. If you don't want this, make sure you only use single arguments when calling in scalar context.

    @strings = ("\thello\n", "\tthere\n");
    $trimmed = trim(@strings);
    # $trimmed = "hello there"

    local $" = ', ';
    $trimmed = trim(@strings);
    # Now $trimmed = "hello, there"

    $trimmed = rtrim;
    # $trimmed = $_ minus trailing whitespace

  Undefined values
If any of the functions are called with undefined values, the behaviour is in general to pass them through unchanged. When stringifying a list (calling in scalar context with multiple arguments) undefined elements are excluded, but if all elements are undefined then the return value is also undefined.

    $foo = trim(undef);        # $foo is undefined
    $foo = trim(undef, undef); # $foo is undefined
    @foo = trim(undef, undef); # @foo contains 2 undefined values
    trim(@foo)                 # @foo still contains 2 undefined values
    $foo = trim('', undef);    # $foo is ''

FUNCTIONS

  trim
Removes leading and trailing whitespace from all arguments, or $_ if none are provided.

  rtrim
Like "trim()" but removes only trailing (right) whitespace.

  ltrim
Like "trim()" but removes only leading (left) whitespace.

UNICODE
Because this module is implemented using Perl regular expressions, it is capable of recognising and removing unicode whitespace characters (such as non-breaking spaces) from scalars with the utf8 flag on. See Encode for details about the utf8 flag.

Note that this only applies in the case of perl versions after 5.8.0 or so.

SEE ALSO
Brent B. Powers' String::Strip performs a similar function in XS.

AUTHORS
Matt Lawrence <mattlaw@cpan.org> - Original author and maintainer

Ryan Thompson <rjt@cpan.org> - Co-maintainer, miscellaneous fixes

SUPPORT
<https://github.com/rjt-pl/Text-Trim/issues>: Bug reports and feature requests

<https://github.com/rjt-pl/Text-Trim.git>: Source repository

ACKNOWLEDGEMENTS
Terrence Brannon <metaperl@gmail.com> for bringing my attention to String::Strip and suggesting documentation changes.

LICENSE
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

<http://dev.perl.org/licenses/artistic.html>