Before showing you the code, some notes.

• You are mixing text (the boundary delimiters) and binary data. This is bad
• You are writing out hexadecimal representations of numbers, but you want to save space. This makes little sense
• You should really use pack

Now, I changed the encoding. Now it is:

• one long, for the index length
• the index. Each entry in the index is made of:
  1. one long: the index number
  2. one long: the string length
  3. some bytes: the string itself
• the content, as a series of longs

And now, the code:

Encoder:

#!/usr/bin/perl

@lines = <>;

binmode STDOUT;
$x = 1;
foreach $ln (@lines) {
  @words = split /\s+/, $ln;
  foreach $word (@words) {
    $index{$word} = $x++;
    $count{$word}++;
  }
}

$idx='';
foreach $key (keys %index) {
  $idx.=pack("N(N/a*)",$index{$key},$key);
}

print STDOUT pack("N",length($idx)),$idx;

foreach $ln (@lines) {
  @words = split /\s+/, $ln;
  foreach $word (@words) {
    print STDOUT pack("N",$index{$word});
  }
}
[download]

Decoder:

#!/usr/bin/perl
binmode STDIN;
undef $/;
$i=<>;
$is=unpack "N",$i;
$ind=substr($i,4,$is);$con=substr($i,4+$is);
%index=unpack "(N(N/a))*",$ind;
@con=unpack "N*",$con;
print join(' ',@index{@con});
[download]

Note the use of binmode and the unsetting of $/ (aka input record separator).

-- 
        dakkar - Mobilis in mobile

---

In reply to Re: help needed on encoding a text file by dakkar
in thread help needed on encoding a text file by bfdi533

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! —
  • How do I compose an effective node title?
  • How do I post a question effectively?
  • Markup in the Monastery
• 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:
  	&		&
  	<		&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.