in reply to Writing indexed arrays in to an file and then retrieved

Using Storable:

use Storable;

store(\@array, 'file.ext');

my $aref = retrieve('file.ext');

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JSON is also a good choice, and it's cross language/platform. ie. I can get the data from the file in Python after writing it in Perl:

use warnings;
use strict;

use JSON;

my @array = qw(1 2 3);

open my $wfh, '>', 'file.ext'
  or die "can't open file for writing: $!";

print $wfh encode_json(\@array);

close $wfh;

open my $fh, '<', 'file.ext'
  or die "can't open file for reading: $!";

my $aref = decode_json(<$fh>);

close $fh;

[download]

Replies are listed 'Best First'.
Re^2: Writing indexed arrays in to an file and then retrieved
by perlmuser (Novice) on Oct 29, 2015 at 06:37 UTC

    Thanks Stevieb for the response .. and everyone else .. But somehow it does not work .. or may be i am not doing it right If i print the reg_map variable using the following code 

    for $i ( 0 .. $page_counter-1 ) {
  print " ###### HI $i #### \n";
  eval ( "\$Total_Size = \$\#reg_map${i}");
  print " Total Size = $Total_Size\n";
  for $j1 ( 0 .. $Total_Size ) { 
    eval ("\$Num_elements_in_row  = \@\{\$reg_map${i}\[\$j1\]\}");
    print " Num_elements_in_row $j1 is = $Num_elements_in_row\n";
    for $j3 ( 0 .. $Num_elements_in_row ) {
     eval("print \"Bit 1 :\$i:\$j1:\$j3 is  \$reg_map${i}\[\$j1\]\[\$j
+3\]\n\"");
    }
  }
}

    [download]

    I get the following display

    Total Size = 80

    Num_elements_in_row 0 is = 3

    Bit 1 :0:0:0 is NONE

    Bit 1 :0:0:1 is NONE

    Bit 1 :0:0:2 is NONE

    Bit 1 :0:0:3 is

    Num_elements_in_row 1 is = 4

    Bit 1 :0:1:0 is TEMP

    Bit 1 :0:1:1 is 0

    Bit 1 :0:1:2 is .

    Bit 1 :0:1:3 is 1

    Bit 1 :0:1:4 is

    I used Store as follows

     store(\@reg_map, 'file.ext');my $aref = retrieve('file.ext');

    When i print aref using the code below 

     
for $i ( 0 .. $page_counter-1 ) {
  print " ###### HI $i #### \n";
  eval ( "\$Total_Size = \$\#aref${i}");
  print " Total Size = $Total_Size\n";
  for $j1 ( 0 .. $Total_Size ) { 
    eval ("\$Num_elements_in_row = \@\{\$aref${i}\[\$j1\]\}");
    print " Num_elements_in_row $j1 is = $Num_elements_in_row\n";
    for $j3 ( 0 .. $Num_elements_in_row ) {
     eval("print \"Bit 2 :\$i:\$j1:\$j3 is  \$aref${i}\[\$j1\]\[\$j3\]
+\n\"");
    }
  }
}

    [download]

    I get the following

    ###### HI 0 ####

    Total Size = -1

    ###### HI 1 ####

    Total Size = -1

    I Also tried using JSON as follows 

     
open my $wfh, '>', 'file1.ext'
  or die "can't open file for writing: $!";

print $wfh encode_json(\@reg_map);

close $wfh;

open my $fh, '<', 'file.ext'
  or die "can't open file for reading: $!";

my @aref = decode_json(<$fh>);

    [download]

    But i get an error at the last line :

    malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "pst0\x{4}\x{8}\x{8}1...") at perl_script.pl line 100, <$fh> line 1.

    Any thoughts on this ..

[reply]
[d/l]
[select]

       eval "..."

      now is a good time to stop writing code like that :)

[reply]
[d/l]

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