#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $file_file='file.txt';
my @regexp=(
  qr/\.txt$/,
  qr/\.csv$/,
  qr/\.ini$/,
  qr/\.cnf$/,
);

open(my $in_fh, '<', $file_file) or die("Error open $file_file ($!)\n");

my @files=(
    [ ],
    [ ],
    [ ],
    [ ],
  );

while(my $line=<$in_fh>)
{
  chomp($line);
  my $pos (0..$#regexp)
  {
    if($line=~$regexp[$pos])
    { puhs(@{$files[$pos]},$line); }
  }
}

print Dumper(\@files);