A direct sysread call seems to be >2x faster:

$ ls -sh bigfile.txt
2.8G bigfile.txt

$ cat direct_sysread.pl

use Fcntl qw(:DEFAULT);
use Symbol;

my $file = shift @ARGV;

my $fh = gensym;
sysopen $fh, $file, O_RDONLY;
my $content;
sysread $fh, $content, -s $file;

$ cat file_slurp.pl

use File::Slurp;

my $file = shift @ARGV;
open my $fh, "<", $file or die $!;

my $content = read_file ($file);

$ time direct_sysread.pl bigfile.txt

real    0m1.785s
user    0m0.008s
sys     0m1.776s

$ time file_slurp.pl bigfile.txt

real    0m4.994s
user    0m0.924s
sys     0m4.052s

[download]

citromatik

In reply to Re^2: Most efficient way to load file contents into scalar? by citromatik
in thread Most efficient way to load file contents into scalar? by smallwalrus

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.