Try this:

use strict;
use warnings;

while ( my $line = <DATA> ) {
    next unless $line =~ /\band\b/;
    chomp $line;
    my @words = split /\s+/, $line;
    my $location = 0;
    my @locations;
    foreach ( @words ) {
        $location++;
        push @locations, $location if m/\band\b/;
    }
    local $" = ", ";
    print "Line $.: 'and' appears as word @locations.\n";
}

__DATA__
This is a test and a test and a test.
[download]

I like your code for this one. Just a question though regarding your regex.

Is your m/\band\b/ better than my method of m/^and$/? Wouldn't they be doing exactly the same thing?



"Age is nothing more than an inaccurate number bestowed upon us at birth as just another means for others to judge and classify us"

sulfericacid

There is a difference. Consider the following:

son-and-law
I can't promise anything (and never will).
People should carpool--and in some cases they do--since it saves gas.
[download]

m/^and$/ will miss the 'and' in these cases, even though it is there. I don't know whether the OP wants that or not, as he didn't really specify edge cases. If such edge cases should be disallowed, my code would need a minor modification so as to not attempt to print anything if @locations is empty.




Dave

#!/usr/bin/perl

use warnings;
use strict;

my $wordcount  = 0;
my $linenumber = 0;
my $wordnumber = 0;
my $findword  = "and";

open(FILE, "< input.txt") or die "Cannot open file: $!";
my @lines = <FILE>;
close(FILE) or die "Cannot close file: $!";

foreach my $line (@lines)
{
    $linenumber++;
   
    my @words = split(/\s+/, $line);

    foreach my $word (@words)
    {
       $wordnumber++;

       if ($word =~ m/^and$/)
       {
           print qq(The word "$findword" occured in line $linenumber a
+t word $wordnumber\n);
       }
    }
       $wordnumber = 0;
}
[download]

UPDATE: Fixed word splitting in regards to Enlil's message:

"but split '',$line is probably better than / /, if someone puts two spaces you might want split, / +/,$line =) "

Thanks!

use strict;

my $word = 'and';
while (<DATA>) {
    if (index($_, $word) > -1) {
        while (m/(?:^|[^a-zA-Z'])$word[^a-zA-Z']/gi) {
            print "The word\n$word\noccured in line " . ($.-1) . " as 
+the " .
            ends(scalar(split(/[^a-zA-Z']+/, substr($_, 0, pos($_) - 1
+)))) . " word.\n\n";
        }
    }
}

BEGIN {
    my @ends = ('','st','nd','rd');
    sub ends {
        return $_[0] . @ends[$_[0] % 10] if $_[0] % 10 < 4 && $_[0] % 
+10 > 0 && int($_[0] / 10) != 1;
        return $_[0] . 'th';
    }
}

__DATA__
Four score and seven years ago our fathers brought forth, upon this co
+ntinent, a
new nation, conceived in liberty, and dedicated to the proposition tha
+t "all men
are created equal"

Now we are engaged in a great civil war, testing whether that nation, 
+or any
nation so conceived, and so dedicated, can long endure. We are met on 
+a great
battle field of that war. We have come to dedicate a portion of it, as
+ a final
resting place for those who died here, that the nation might live. Thi
+s we may,
in all propriety do. But, in a larger sense, we can not dedicate -- we
+ can not
consecrate -- we can not hallow, this ground -- The brave men, living 
+and dead,
who struggled here, have hallowed it, far above our poor power to add 
+or detract.
The world will little note, nor long remember what we say here; while 
+it can
never forget what they did here.
[download]