I'm returning it in a function call...

In case the string is huge and you want to avoid some temporary memory allocation (which could push up the peak memory usage of the program), you could return a reference to the scalar: 

#!/usr/bin/perl

sub mem {
    print "$_[0]:\n";
    system "/bin/ps", "-osize,vsize", $$;
}

sub foo {
    mem(0);
    my $data;
    $data .= "xxxxxxxxxx" for 1..1_000_000;
    mem(1);
    return \$data;  # return reference
}

my $r = foo();  # then get at the data using $$r
mem(2);

__END__
$ ./880173.pl
0:
   SZ    VSZ
  612  19804
1:
   SZ    VSZ
10468  29660
2:
   SZ    VSZ
10468  29660

[download]

Using the same snippet, but with return $data, you'd get: 

0:
   SZ    VSZ
  612  19804
1:
   SZ    VSZ
10468  29660
2:
   SZ    VSZ
20236  39428

[download]

As you can see, the process size has grown additionally by about the size of $data.

Whether this really saves anything overall depends on what else the program is doing to actually print the string, etc.

In reply to Re: Most efficient way to print a file? by Anonyrnous Monk
in thread Most efficient way to print a file? by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.