Ah! Of course! I wasn't resetting the filehandle! (Must. . . have. . . coffee. . ) The filehandle SORTD refers a textfile like this: 
0912203749
0725284648
0608294149
0622424347
1219303436
1729313449
1015162331
 . . .

[download]
These are actually groupings of five 2-digit numbers. My goal was to traverse it by column, using i*2 as a starting index (that part, at least, works fine). I probably should have explained that at the outset but, silly me, I thought the issue was probably too simple to require further elaboration (I won't make that mistake again). Bountiful thanks, CountZero!

In reply to Re^2: For- loop increment not passing to inner block by Anonymous Monk
in thread For- loop increment not passing to inner block 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.