in reply to Re: perl parsing
in thread perl parsing

Thank I am understanding a bit better now, but I tried your solution , mainly the HOH printing but I am getting error.."Not a Hash reference at line 42

foreach my $line(keys %hash)  
{
   print "$line\n";  ##This works and prints the names
   
   foreach my $sit (keys %{$hash{$line}}) #### <--line 42 line throwin
+g error
   {
       print "$hash{$line}{$sit}\n";   
   }

}

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Re^3: perl parsing
by Marshall (Canon) on Oct 06, 2017 at 05:13 UTC
    Show your complete code. I can't tell what your problem is from this snippet.

    I avoided a HoH (Hash of Hash) in my first code post partly because as I suspected beginners have problems with this. You are proving me right.

    I suggest that use perhaps my first code that doesn't use any complicated data structures. That will be easier for you to work with?

    This code took me some minutes to write. It very well could be that it will take you literally hours to understand it. You will not learn if you don't put in the effort.

[reply]

      Thank you for taking the time to assist me with this.I want to learn the HOH method, so I will try to use that in my solution with your aid.Using "print Dumper \%hash;" works and te HOH has all the info I need but I can't seem to print it out in a format I want . name device(s) <space> year My entire code is 

      #!/usr/bin/perl

use strict;
use Data::Dumper;

my $infile = 'test_file.txt';
open (IN,'<',$infile) || die ("Could not open $infile : $!");
my $name;
my %hash = ();

while (<IN>){
  s/^\s+|\s+$//g; # trim leading/trailing spaces
  my ($col1,$col2,$col3) = split /\s+/,$_,4;
  if ($col1 eq 'name'){
    $name = $col2;
    
 } elsif ($col1 eq 'device') 
    {
    push @{$hash{$name}},$col2,$col3;
  } 
else 
{
    # skip line
  }

##
##
}
close IN;



#print Dumper \%hash;

foreach my $line (keys %hash)
{
print "$line\n";

    foreach my $sit (keys %{$hash{$line}})
        {
        print "$hash{$line}{$sit}\t$sit";
            }
}

      [download]

      DATA

      name Brian
device Ipad 2001
device  iphone 2000
number 2
name Jason
device computer 2011
number 1
name Andrew
device ipad 1999
device iphone 1990

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        Change this line to build a Hash of Arrays (HoA)

        #push @{$hash{$name}},$col2,$col3;
push @{$hash{$name}},"$col2\t$col3"; # device year

        [download]

        and change the output loop to

        foreach my $name (keys %hash){
  print "$name\n";
  foreach my $sit (@{$hash{$name}}){
    print "\t$sit\n";
  }
}

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        poj
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