changing a hash value from string to array

Question

data.txt

 Name:xyz
 ID:1
 Value: 1 2 3 4 5 6 7 8 9 ...
 ID:2 
 Value: 9 8 7 6 5 4 3 2 1..
 ID:3
 Value: 90 89 88....
 Name:abc
 ID:11
 value:...

Intial file.txt

## Header 
..
data
data
data
..

Final expected file.txt

## Header xyz_1,xyz_2,xyz_3,abc_11,...
..
data 1 9 90
data 2 8 89
data 3 7 88
data 4 6 
..

Current output file.txt

## Header xyz_1,xyz_2,xyz_3,abc_11,...
...
data, 1 2 3 4 5 6 7 8 9 ..,9 8 7 6 5 4 3 2 1 ..,90 89 88
data
data
...

Code

#!/usr/local/bin/perl
use diagnostics;
use strict;
use warnings;

use Tie::File;

my @name_id;
my %test;

#local $/ = '';

open my $fh, '<', 'data.txt' or die "failed: $!";
my %var;
while (<$fh>) {
  chomp;
  if (m/^([A-Z:]+):\s*(.*)/) {
    $var{$1} = $2;
    if (exists($var{Name}) && exists($var{ID}) && exists($var{value}) && $1 eq 'value') {
      my $var_name = "$var{Name}_$var{ID}";
      push @name_id, $var_name;
      $test{$var_name} = $var{value};
    }
  }
}

#   print join "\n\t", @test{@name_id};
my $match = "## Header";
tie my @lines, 'Tie::File', 'file.txt' or die "failed : $!";
for my $line (@lines) {
  if ($line =~ /^($match.*)/) {
    $line = $1 . "," . join ',', @name_id;
  }
}
untie @lines;

my $match = "data";
tie my @lines, 'Tie::File', 'file.txt' or die "failed : $!";
my $i = 0;
for my $line (@lines) {
  if ($line =~ /^($match.*)/) {
    $line = $1 . "," . join(',', map { $test{$_}->[$i] } @name_id);
    $i++;
  }
}
untie @lines;

Have a problem with this line $line = $1 . "," . join (',', map { $test{$_}->[$i]} @name_id); it throws the error

Can't use string ("1 2 3 4 5 6 7 8 9 .."...) as an ARRAY ref while "strict refs" in use at test.pl line 46, line 80. at test.pl line 46

I think the hash(%test) value I had is a string and I can't split it as an array. Please let me know how to convert it to an array. I tried doing $test{$var_name} = [qw($var{value})]; it didnt work.

Why would you mix $i and $1 in the same code together? Why :(. Please rename. — BLaZuRE
– BLaZuRE, Commented Jun 4, 2013 at 22:52

Borodin · Accepted Answer · 2013-06-05 02:10:10Z

You may be interested in this refactoring of your code that seems to do what you want.

#!/usr/local/bin/perl
use strict;
use warnings;

use Tie::File;

open my $fh, '<', 'data.txt' or die "failed: $!";

my @name_id;
my %test;
my %var;

while (<$fh>) {
  chomp;
  if (my ($key, $val) = /^(\w+):\s*(.*)/) {
    $var{$key} = $val;
    if ($key eq 'value') {
      my $var_name = "$var{Name}_$var{ID}";
      push @name_id, $var_name;
      $test{$var_name} = [ split ' ', $var{value} ];
    }
  }
}

tie my @lines, 'Tie::File', 'file.txt' or die "failed : $!";
my $count = 0;
for my $line (@lines) {
  if ($line =~ /^## Header/) {
    $line .= ' ' . join ',', @name_id;
  }
  elsif ($line =~ /^data/) {
    $line .= ' ' . join ' ', map { $test{$_}[$count] // '' } @name_id;
    $count++;
  }
}
untie @lines;

output (file.txt)

## Header xyz_1,xyz_2 ,xyz_3
data 1 9 90
data 2 8 89
data 3 7 88
data 4 6

mzedeler · Accepted Answer · 2013-06-04 23:01:21Z

1

This is surely not right:

$test{$_}->[$i]

Because $test{$_} can only contain a string of some sort.

If you have a string and want to split into an arrayref so the above works, do this:

$test{$var_name} = [split /\s+/, $var{value}];

I have no idea what the code is supposed to accomplish which means that it may run, but I can't tell if it does what it is meant to. The odd variable names (like $test and $var_name didn't help me to understand the purpose).

answered Jun 4, 2013 at 23:01

mzedeler

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2 Comments

user2441289 Over a year ago

it worked. Thats what I need although it complains for ` $line = $1 . "," . join (',', map { $test{$_}->[$i]} @name_id);` Use of uninitialized value in join or string at test4.pl line 47, <$fh> line 141 (#1)

mzedeler Over a year ago

Maybe you can reopen a new question with the new code. I still think you should clean up the variable names, by the way.

Chris Charley · Accepted Answer · 2013-06-04 23:37:22Z

I'm not too sure I followed your code, but I thought I'd post how to transpose the numbers (unless your code already does that :-) ).

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

my (%data, $name);
while (<DATA>) {
    if (/^Name:(.+)/) {
        $name = $1  
    }
    elsif (/^Value/) {
        # transpose
        my $r = 0;
        push @{ $data{$name}[$r++] }, $_ for /\d+/g;
    }   
}

use Data::Dumper; print Dumper \%data;

__DATA__
Name:xyz
ID:1
Value: 1 2 3 4 5 6 7 8 9
ID:2 
Value: 9 8 7 6 5 4 3 2 1
ID:3
Value: 90 89 88 87 86 85 84 83 82
Name:abc
ID:11

The dumped results are:

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