What do you mean field? col?

?? does this help Identifying the position of match using regular expressions

 if ($data1 =~ /Item | volume/) { ...

that can only match item or volume, not both

• #!/usr/bin/perl --
  use strict; use warnings;
  my $data = "Region Item volume Month";
  my @da = split /\s+/, $data;
  for my $daix ( 0 .. $#da ){
      $_ = $da[$daix];
      /volume/        and print "volume $daix\n";
      /Item/          and print "Item $daix\n";
      /(volume|Item)/ and print "$1 $daix\n";
  }
  __END__
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• #!/usr/bin/perl --
  use strict; use warnings;
  my $data = "Region Item volume Month";
  my @da = split /\s+/, $data;
  my $daix = 0;
  for( @da ){
      /volume/        and print "volume $daix\n";
      /Item/          and print "Item $daix\n";
      /(volume|Item)/ and print "$1 $daix\n";
      $daix++;
  }
  __END__
  [download]

• #!/usr/bin/perl --
  use strict; use warnings; use 5.012;
  my $data = "Region Item volume Month";
  my @da = split /\s+/, $data;
  while( my($daix, $_) = each @da ){
      /volume/        and print "volume $daix\n";
      /Item/          and print "Item $daix\n";
      /(volume|Item)/ and print "$1 $daix\n";
  }
  __END__
  [download]

Thomas Kennll:

You've got plenty of answers already, so I'll just play around a little:

$ cat u.pl
my $data = "Region Item volume Month";
my %h = do {my $cnt=0; map {$_=>++$cnt} split /\s+/, $data};
print "$_  $h{$_}\n" for grep {exists $h{$_}} qw(Item volume Tuba);

$ perl u.pl
Item  2
volume  3
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The hash maps the fields with the field index. Wrapping the right hand side of the hash assignment in a do statement lets me localize a temporary variable. Preincrementing the temp variable converts the field numbers to one-based numbering.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

1. What is the source format of your data; a database, an html table, a doc table, a spreadsheet, a csv file?
2. How are you making the data available to perl; slurping a file; reading line by line, db Row by Row or field by field?

Your my $data = "Region Item volume Month" if ($data1= .... makes me think you're trying to step thru an array where the elements (scalars) $data0,$data1, $data2 (etc) each contain the items you want and two more... (in which case the array after "my" needs an @ sigil rather than $). If that's in fact the case, have you mastered moving the data from its source to your script? And if so, then a for loop;split and (since your regex is borked, as noted above) perlretut should help.

What you've provided (as of this writing) just isn't enough to be sure these suggestions are on track. So please update your question (and mark the update ). And even pseudo-code benefits from using required elements like semi-colons.

anonymous's split : the better ones. mine ... not so good.

use strict;
use warnings;
use Data::Dumper;
use 5.010;

my $data = "Region day Item volume Month district piece amount day ...
+ one more test";
print "$data\n";

my (@sep);
push @sep, 0;
push @sep, $-[0] while( $data =~ /\s+/g );
push @sep, length($data);

while( $data =~ /Item|volume|day|test/g ){
    #printf "%s|%s|%s,matched pos=%s\n", $`,$&,$',$-[0];
    my $match_bgn = $-[0];
    for( my $idx=0 ; $idx < $#sep; $idx ++){
        # printf "match pos=%d, %d .. %d\n"
        #,$match_bgn ,$sep[$idx] ,$sep[$idx+1];
        if( $match_bgn > $sep[$idx] && $match_bgn < $sep[$idx+1]) {
            print "col of $&=$idx\n";
        }
    }
}
__DATA__
Region day Item volume Month district piece amount day ... one more te
+st
col of day=1
col of Item=2
col of volume=3
col of day=8
col of test=12
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