B Bu But it works for me? My "perl -v" insists it is 5.8.0. What version of Perl are you running? I changed the test program input and format to more closely mirror what you wanted. 
  $str = "\000\005ABC\000\004DE\000\003F";
  $fmt = "(n XX /a)*";
returns 
'0', '5', '65', '66', '67'
'0', '4', '68', '69'
'0', '3', '70'
Also tried it with "(nXX/a)*" with same results. When you run the same program does it get different results or a syntax error? You said it doesn't parse? As in it doesn't split the input correctly? Could it be a big/little-endian problem?

(shenme wants to know if the battery in his new toy has run down)

In reply to Re^3: Unpacking fixed length records by shenme
in thread Unpacking fixed length records by diotalevi

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.