use strict;

my $count = 1;
my $line  = 0;

while (<DATA>)
{
  $line++;

    $count = 1, next
        if /^<main>/;
    
    die "out of order at line $line!" if
        /<sub(\d+)>/ && $1 != $count++;
}

__DATA__
<main>Ability-oriented motivation, 00206.p0105
<main>Ability test
<sub1>in conjunction with achievement batteries, 00226.p0085
<sub3>definition, 00226.g0005
<main>Aboriginal athletes, 00954.p0155
<sub2>Absolutism, 00688.p0010

[download]

holli, regexed monk

In reply to Re: How to validate file format by holli
in thread How to validate file format by gube

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.