Re: Smart way to read a file vertically?

[johngg]

in reply to Smart way to read a file vertically?

Similar to other solutions but using push with a ternary and maps.

use strict;
use warnings;

use 5.010;

open my $inFH, q{<}, \ <<'EOD' or die qq{open: < HEREDOC: $!\n};
NAME    LAST_NAME    PHONE    EMAIL
John    Smith    1234    [e-mail]
Peter    Jones    6789    [e-mail]
George    Lukas    9086    [e-mail]
EOD

my( @N, @LN, @P, @E );
push @{
   $_->[ 0 ] == 1
   ? \ @N
   : $_->[ 0 ] == 2
     ? \ @LN
     : $_->[ 0 ] == 3
       ? \ @P
       : \ @E
   }, $_->[ 1 ] for
   map {
       chomp;
       my $col = 0;
       map { [ ++ $col, $_ ] } split m{\t};
       }
   <$inFH>;

close $inFH or die qq{close: < HEREDOC: $!\n};
say for @N, q{}, @LN, q{}, @P, q{}, @E;

The output.

NAME
John
Peter
George

LAST_NAME
Smith
Jones
Lukas

PHONE
1234
6789
9086

EMAIL
[e-mail]
[e-mail]
[e-mail]

I hope this is of interest.

Update: As pointed out by Not_a_Number, the code would have failed for some names. I had forgotten to put tabs back into the data after the copy'n'paste put in the displayed spaces :-(

Code now corrected.

[Not_a_Number]

Fails for 'Mary Lou Retton' and 'Ludwig van Beethoven'