Maintainability notes:
  1. Include the name of the file in the error message. Just knowing that you failed because , "No such file or directory" is not nearly as useful as knowing which file purportedly does not exist.
  2. Why put the lines into an array? It is just as easy to read from the file directly, and that gives you the option of reading it incrementally with a while loop. (Huge improvement on large files.)
  3. Indentation?
  4. You forgot to chomp the lines from the file.
  5. I find that using a hash slice rather than a list of variables is much more maintainable. That way minor (or major) data format changes are much easier to handle.
With those changes this example would become something like: 
#! perl
use strict;
my $file = shift(@ARGV) || "foo.txt";
open(FH, $file) or die("Cannot read '$file': $!");

my @field_list = qw(put in reasonable names here for your data);
while (<FH>) {
  chomp;
  my %row;
  @row{@field_list} = split /\|/, $_;
  my ($field_data, $comment) = split /;/, $row{data};
  print "$field_data\n";
}

[download]
Of course the original author should switch to a data format which is self-documenting (for instance make the first line a header line that says what fields are in use). And when you do that, the use of a hash slice makes things very easy - just read the list of field names out of the header line!

In reply to Re (tilly) 2: Database question: pulling a particular field from a flat database by tilly
in thread Database question: pulling a particular field from a flat database by koacamper

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.