#!/usr/bin/perl

use strict;
use warnings;

my @GREPLIST = grep {!/^[\+\-\~]/} @ARGV;
my @SKIPLIST = grep {s/^~//} @ARGV;
my $DEBUG = grep {/^-d/} @ARGV;
my $IGNORECASE = grep {/^-i/} @ARGV;
(my @POSITIONS) = grep {s/^\+//} @ARGV;

# add this to regexp with ignore case
if($IGNORECASE){
  grep { s/^/(?i)/ } @GREPLIST;
}

print "# POSITIONS=@POSITIONS;IGNORECASE=$IGNORECASE;GREPLIST=@GREPLIST;SKIPLIST=@SKIPLIST\n" if $DEBUG;

# arrays start with zero, so decrease field numbers by 1
--$_ for @POSITIONS;

LINE: while(<STDIN>){
  for my $re (@GREPLIST){
    print "# $re =~ $_" if ($DEBUG);
    next LINE unless m/$re/;
  }
  for my $re (@SKIPLIST){
    print "# $re !~ $_" if ($DEBUG);
    next LINE if m/$re/;    
  }
  chomp;
  if(@POSITIONS){
    # print all fields in the requested order
    print join(" ", +(split /\s+/)[@POSITIONS]);
  }else{
    # just print the whole line
    print 
  }
  print "\n";
}

##</code><code>##

cat ~/a | ./gggrep.pl country city1 street1 ~name1 -i +5
name2
name3


cat ~/a | ./gggrep.pl -i country city1 street1 ~name1 +2 +5
City1 name2
City1 name3