#!/usr/bin/perl
#web_search -- a program to simulate how sites index the 'Net.
#invocation: <web_search *.pl> to index all the *.pl files
#in the current directory.

use strict;

my %words;

### Index the files

undef $/; #file slurp mode

for my $name (@ARGV)
{
    open F,"<$name" or die "couldn't open $name\n";

    map { push( @{$words{$_}}, $name) } split(/\s+/, <F>);
    
    #print "$_ -> @{$words{$_}}\n" for keys %words; #pretty print
}

### Ask for search keywords

$/="\n"; #unslurp for user input

print "\nEnter you list of search words: ";

open I, "-";

while(<I>)
{
    for (split)
    {
        if (defined($words{$_}))
        {
            print "$_ found in ".join(", ",@{$words{$_}})."\n";
        }else
        {
            print "$_ not found\n";
        }
    }
}
[download]