in reply to Re: Parse a file and store it in hash of hashes
in thread Parse a file and store it in hash of hashes

This is my code snippet. When i run this program there is no output at all. I am not able to figure out why 

#!/usr/local/bin/perl
use strict;
use warnings;
use Data::Dumper;

        my $filename = 'tester.txt'; 
        my %HoH; my $key; my $value;
        open(my $fh, '<:encoding(UTF-8)', $filename)
        or die "Could not open file '$filename' $!";
        while ( <$fh> ) {
        next unless s/^\[(.*?)\]\s*//;
        $rec = $1;
        for my $field ( split /\n/) {
        ($key, $value) = split /\s*=\s*/, $field;
        $HoH{$rec}{$key} = $value;
    }
}
print Dumper %HoH;

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Re^3: Parse a file and store it in hash of hashes
by Corion (Patriarch) on Jan 16, 2017 at 08:34 UTC

    I find this highly unlikely. When I run your code, I get the following output:

    Global symbol "$rec" requires explicit package name at q:\tmp.pl line 
+12.
Global symbol "$rec" requires explicit package name at q:\tmp.pl line 
+15.
Execution of q:\tmp.pl aborted due to compilation errors.

    [download]

    If I declare $rec as lexical variable and create an empty filename tester.txt, I get no output. This is because you're not using Data::Dumper properly

    print Dumper %HoH;
# should be
print Dumper \%HoH;

    [download]

    Please post the actual code you are using.

    Also, look at Config::IniFiles, which does all of what you're doing already.

[reply]
[d/l]
[select]

      That $rec was a typo. I have edited the code again. After I tried using Data::Dumper as you said I am getting the following output. I want to solve the problem using the HoH approach only so I have not used Config::Inifiles.

      $var1 = {};
[reply]
[d/l]
Re^3: Parse a file and store it in hash of hashes
by Discipulus (Canon) on Jan 16, 2017 at 08:43 UTC
    Hello Sonali and welcome to the monastery and to wonderful world of Perl!

    First of all follow the wise suggestions of the precise monk afoken.

    That said, with the code you posted, and in particular $rec = $1 I get the error Global symbol "$rec" requires explicit package name at pm16012017.pl line 12. but is probably a typo.

    In addition i think you just need a hash not a HashOfHash.

    Now about your code: if next unless s/^\[(.*?)\]\s*//; is intended to skip the first line must probably be: next if s/^\[(.*?)\]\s*//;

    Even with this you get errors about undefined values: Use of uninitialized value in hash element at inifile16012017.pl line 15, foreach line of data and the following datastructure:

    $VAR1 = '';
$VAR2 = {
          'FIFTH' => '12345',
          'COMMENT' => '"Perl parsing"',
          'SEVENTH' => 'QWERTY',
          'FOURTH' => '"RANDOM"',
          'SECOND' => '"ID"',
          'FIRST' => '"TEST"',
          'THIRD' => '123',
          'SIXTH' => '6789'
        };

    [download]

    If you intended to have CELL_NAME as root element you need to not skip the line with it and have $rec declared outside the loop, to have it ad disposal during the loop: 

    my $rec;
        while ( <$fh> ) {
        if (s/^\[(.*?)\]\s*//){$rec = $1}

    [download]

    The resulting datastructure (dumped with Data::Dump with dd prettier method) will be:

    (
  "CELL_NAME",
  {
    COMMENT => "\"Perl parsing\"",
    FIFTH   => 12345,
    FIRST   => "\"TEST\"",
    FOURTH  => "\"RANDOM\"",
    SECOND  => "\"ID\"",
    SEVENTH => "QWERTY",
    SIXTH   => 6789,
    THIRD   => 123,
  },
)

    [download]

    L*

    There are no rules, there are no thumbs..
    Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
[reply]
[d/l]
[select]

      Yes you were correct about the typo at line 12. But I need HoH because my file is a collection of cell values like shown below. I had only posted one of the cells.

      [CELL_NAME1]
COMMENT           = "Perl parsing"
FIRST             = "TEST1"
SECOND            = "ID1"
THIRD             = 123
FOURTH            = "RANDOM"
FIFTH             = 12345
SIXTH             = 6789
SEVENTH           = QWERTY

[CELL_NAME2]
COMMENT           = "Tester"
FIRST             = "TEST2"
SECOND            = "ID2"
THIRD             = 1234
FOURTH            = "FOUR"
FIFTH             = 12345
SIXTH             = BOARD
SEVENTH           = MOUSE

[CELL_NAME3]
COMMENT           = "Parser"
FIRST             = "TEST3"
SECOND            = "ID3"
THIRD             = 12345
FOURTH            = "FIVE"
FIFTH             = 12345
SIXTH             = PAD
SEVENTH           = KEY

      [download]

      I need to generate a HoH structure for this.

[reply]
[d/l]
        The answer is already there
        Read more... (1331 Bytes)

        L*

        There are no rules, there are no thumbs..
        Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
[reply]
[d/l]

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