Re: searching an array member in file header and print a column

[2teez]

Hi shalgham,
Without removing anything from previous great post, I think ( that is if I get your question right ) what you need do is get the index of the column you wanted and print it out. Since all the values for the column you wanted follow the same.
Something like this, using a modified data given by InfiniteSilence

#!/usr/bin/perl -l
use warnings;
use strict;

# get the header into an array
my @header = split /\s+/, <DATA>;

# conjure a regex using the name of columns you wanted
# which is the array you have
my $to_find = join( '|' => qw(nat pls kac) );
my $reg_to_use = qr/$to_find/;

# get the index of the header you need
my @index = grep { $header[$_] =~ /$reg_to_use/ } 0 .. $#header;

print join( "\t" => @header[@index] );

while (<DATA>) {
    print join( "\t" => ( split /\s+/, $_ )[@index] );
}

__DATA__
nat     pls     fof     tri     pls     fof     tri    kac
0.1     0.1     0.23    0.1    0.1     0.23    0.1    0.31
2.3     1.8     3.2     4.4     1.8     3.2     4.4    3.21
5.5     3.2     8.6.    7.9     3.2     8.6.    7.9    2.89

Output:

nat    pls    pls    kac
0.1    0.1    0.1    0.31
2.3    1.8    1.8    3.21
5.5    3.2    3.2    2.89

Note: I don't know how your real dataset looks like, and the above 'might' not be the best in your situation but I can only hope this gives a head up.