put .txt files into a hash and compare with an array of words using perl

Question

I have a folder of .txt files which I want to store in a hash. Then compare the file against an array of specific words. While counting the amount of times the specific words occur.

Answer 1

Note that I use \p{Alpha} because that technically defines a word. You can monkey with the regex to add numbers or make sure that there is one alpha at the beginning or whatever you're likely to need.

Note also that for files consisting of one word per line, the regex is overkill and you should omit it. Just chomp the line and store $_.

use 5.010; # for say
use strict;
use warnings;

my ( %hash );

sub load_words { 
    @hash{ @_ } = ( 0 ) x @_; return; 
}

sub count_words {
    $hash{$_}++ foreach grep { exists $hash{$_} } @_;
}


my $word_regex
    = qr{ (                # start a capture
            \p{Alpha}+     # any sequence of one or more alpha characters
            (?:            # begin grouping of
                ['-]         # allow hyphenated words and contractions
                \p{Alpha}+   # which must be followed by an alpha
            )*             # any number of times
            (?: (?<=s)')?  # case for plural possessives (ht: tchrist)
          )                # end capture
        }x;

# load @ARGV to do <> processing
@ARGV = qw( list of files I take words from );
while ( <> ) {
    load_words( m/$word_regex/g );
}
@ARGV = qw( list of files where I count words );
while ( <> ) { 
    count_words( m/$word_regex/g );
}

# take a look at the hash
say Data::Dumper->Dump( [ \%hash ], [ '*hash' ] );

Answer 2

Not going to write the code for you, but you could do something like:

1. Loop all the files (see glob())
2. Loop all the words in each file (maybe with a regular expression or split()?)
3. Check each words against a hash of wanted words. If it's there, increment a "counter" hash value as such: $hash{ $word }++ OR you could store all the words in a hash and then grab the ones you want afterwards ..

OR ... there are many ways to do it..

If your files are huge you will have to do it another way

Answer 3

So I got it done Using an array of the specific words I wanted to find... HAPPY DAYS :-)

#!/usr/bin/perl
#use strict;
use warnings;
my @words;

my @triggers=(" [kK]ill"," [Aa]ssault", " [rR]ap[ie]"," [dD]rug");
my %hash;

sub count_words {
    print "\n";
}

my $word_regex
    = qr{ (                # start a capture
            \p{Alpha}+     # any sequence of one or more alpha characters
            (?:            # begin grouping of
                ['-]         # allow hyphenated words and contractions
                \p{Alpha}+   # which must be followed by an alpha
            )*             # any number of times
          )                # end capture
        }x;

my @files;
my $dirname = "/home/directory";
opendir(DIR,$dirname) or die "can't opendir $dirname: $!";
while (defined($file = readdir(DIR))) {
     push @files, "$dirname$file";
}    # do something with "$dirname/$file" } 
closedir(DIR);
my @interestingfiles;

foreach $file (@files){

    open FILE, ("<$file") or die "No file";

    foreach $line (<FILE>){
        foreach $trigger (@triggers){
           if($line =~ /$trigger/g){
              push @interestingfiles, "$file\n";
           }
        }
    } 
   close FILE;
}
print @interestingfiles;