How to use Perl's File::Grep module - perl

Question

I am using the File::Grep module. I have following example:
#!/usr/bin/perl
use strict;
use warnings;
use File::Grep qw( fgrep fmap fdo );
my #matches = fgrep { 1.1.1 } glob "file.csv";
foreach my $str (#matches) {
print "$str\n";
}
But when I try to print $str value it gives me HEX value: GLOB(0xac2e78)
What's wrong with this code?

Answer 1

The documentation doesn't seem to be accurate, but judging from the source-code — http://cpansearch.perl.org/src/MNEYLON/File-Grep-0.02/Grep.pm — the list you get back from fgrep contains one element per file. Each element is a hash of the form
{
filename => $filename,
count => $num_matches_in_that_file,
matches => {
$line_number => $line,
...
}
}
I think it would be simpler to skip fgrep and its complicated return-value that has way more information than you want, in favor of fdo, which lets you just iterate over all lines of a file and do what you want:
fdo { my ( $file, $pos, $line ) = #_;
print $line if $line =~ m/1\.1\.1/;
} 'file.csv';
(Note that I removed the glob, by the way. There's not much point in writing glob "file.csv", since only one file can match that globstring.)
or even just dispense with this module and write:
{
open my $fh, '<', 'file.csv';
while (<$fh>) {
print if m/1\.1\.1/;
}
}

Answer 2

I assume you want to see all the lines in file.csv that contain 1.1.1?
The documentation for File::Grep isn't up to date, but this program will put into #lines all the matching lines from all the files (if there were more than one).
use strict;
use warnings;
use File::Grep qw/ fgrep /;
$File::Grep::SILENT = 0;
my #matches = fgrep { /1\.1\.1/ } 'file.csv';
my #lines = map {
my $matches = $_->{matches};
#{$matches}{ sort { $a <=> $b } keys %$matches};
} #matches;
print for #lines;
Update
The most Perlish way to do this is like so
use strict;
use warnings;
open my $fh, '<', 'file.csv' or die $!;
while (<$fh>) {
print if /1\.1\.1/;
}