in all honesty, my brain gives up on at least three things - quantum physics, Trump-supporters, and type-globs...

Thanks for making me laugh. :) I'm relieved you didn't mention your brain giving up on use strict, use warnings and lexical variables. You really need to embrace all three. To give a simple example why, notice that this code: 

use strict;
use warnings;
sub fred {
    my $fname = 'f.tmp';
    open( FH, '<', $fname ) or die "error: open '$fname': $!";
    print "file '$fname' opened ok\n";
    # ... process file here
    die "oops";   # if something went wrong
    close(FH);
}
eval { fred() };
if ($@) { print "died: $@\n" }
# oops, handle FH is still open if an exception was thrown.
my $line = <FH>;
print "oops, FH is still open:$line\n";

[download]
is not exception-safe because the ugly global file handle FH is not closed when die is called.

A simple remedy, as noted at Exceptions and Error Handling References, is to replace the ugly global FH with a lexical file handle my $fh, which is auto-closed at end of scope (RAII): 

use strict;
use warnings;
sub fred {
    my $fname = 'f.tmp';
    open( my $fh, '<', $fname ) or die "error: open '$fname': $!";
    print "file '$fname' opened ok\n";
    # ... process file here
    die "oops";   # if something went wrong
    close($fh);
}
eval { fred() };
if ($@) { print "died: $@\n" }
print "ok, \$fh is auto-closed when sub fred exits (normally or via di
+e)\n";

[download]

In reply to Re^3: Filehandles and CSV_XS by eyepopslikeamosquito
in thread Filehandles and CSV_XS by Melly

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.