Hi, I'm having trouble understanding why the following code doesn't work as expected. Any help would be appreciated. 
#!/usr/bin/perl

my $tf = shift;        # any random text file. Say, /etc/passwd

open(MF, "< $tf") || die "Unable open $tf for input: $!";

# this doesn't work
#
my %opt;
$opt{'M'} = *MF;
while (<$opt{'M'}>) {
    print "loop one...\n";
}

# this doesn't work
#
my @opt;
$opt[0] = *MF;
while (<$opt[0]>) {
    print "loop two...\n";
}

# this does work
#
my $tf = *MF;
while (<$tf>) {
    print "loop three...\n";
}

[download]

In reply to hashs and file handle globs by jroberts

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.