OK, my most recent school project involved writing our own limited shell.

I've basically coded everything except the |,<, and > operators.

These are a bitch, because I hate dealing with pipes that refuse to be bi-directional. I think the solution has something to do with something called "dup"ing, though I haven't a clue how.

To explain more specifically, say I'm trying to code the "<" operator...I have to get something like

wc < sometext

to output the right thing, but I can't use the "<" opeartor in my code itself. Thus here's my attempt so far:

open (PIPE,"| $path/$command >&RESULT");
print PIPE @data;
close(PIPE);
@result = <RESULT>;

[download]

This is course doesn't work at all, but maybe it gives u an idea of what I need. I have to be able to pass @data (like sometext) in a given command (like wc) and capture the result in an array (@result). I've tried soooooo many different things and keep failing. I am at your mercy :)

In reply to Dup & redirecting filehandles by Magius_AR

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.