I'm trying to craft a script that will "tidy" up JSON, but am running into issues. The following script I've half-hazardly banged out inserts indents and newlines along any braces, but it doesnt take into account braces within quoted data, or indent regular name/value pairs, and I'm not quite sure of how to go about doing that... 
#!/usr/bin/perl

use strict;
use warnings;

# if first argument isnt a valid input file, die
die("USAGE: $0 [input file]\n") if (! -f $ARGV[0]);

# initialize some vars
my $indent = my $sbrace = my $cbrace = 0;

# slurp input file contents
my $contents;
{
  local $/ = undef;
  open(my $IN, '<', $ARGV[0]) or die("couldn't open file: $!");
  $contents = <$IN>;
  close($IN);
}

# regex match every brace (with an optional trailing comma), evaluatin
+g replace as sub
$contents =~ s/([\{\}[\],],?)/indent_brace($1)/egmsx;
$contents =~ s/\n+/\n/g;

# print out entire file to original filename plus '.out'
open(my $OUT, '>', $ARGV[0].'.out') or die("couldn't open file: $!");
print {$OUT} $contents;
close($OUT);

# where the REAL work is done
sub indent_brace {
  # split into array of chars
  my @match = split //, shift;
  
  # define it in local scope
  my $result;

  # decrement indent and appropriate brace count
  if($match[0] eq ']' || $match[0] eq '}') {
    $indent--;
    $sbrace-- if $match[0] eq ']';
    $cbrace-- if $match[0] eq '}';
  }
  
  # inject newlines and indenting tabs
  if($match[0] eq ',') {
    $result = join '', @match, "\n";
  }
  else {
    $result = join '', "\n", "\t"x$indent, @match, "\n";
  }
  
  # increment indent and appropriate brace count
  if($match[0] eq '[' || $match[0] eq '{') {
    $indent++;
    $sbrace++ if $match[0] eq '[';
    $cbrace++ if $match[0] eq '{';
  }
  
  return $result;
}

[download]
Following is example JSON data, note the difficulties in that there may be braces and brackets within the quoted strings, as well as backslash-escaped quotes, which requires a much more complex regular expression (if that is even the way to go). 
# untidy
{"DDATE_ALPHA":"08\/17\/2007","TTIME_ALPHA":"18:23:09.592","IID_ALPHA"
+:"[3858f62230ac3c915f300c664312c63f]","VDATA_ALPHA":[5,226426,565,224
+5,76437,754,3526,87245,6565,757,775,7563,3226,564572,45526,673,5278,1
+1584,556],"AAUTH_ALPHA":false,"RREF_ALPHA":null,"NNAME_ALPHA":"Versio
+n \"0\", \"5\", \"19\""}

# tidied up by hand (what I want the script output to look like)
{
    "DDATE_ALPHA":"08\/17\/2007",
    "TTIME_ALPHA":"18:23:09.592",
    "IID_ALPHA":"[3858f62230ac3c915f300c664312c63f]",
    "VDATA_ALPHA":[
        5,
        226426,
        565,
        2245,
        76437,
        754,
        3526,
        87245,
        6565,
        757,
        775,
        7563,
        3226,
        564572,
        45526,
        673,
        5278,
        11584,
        556
    ],
    "AAUTH_ALPHA":false,
    "RREF_ALPHA":null,
    "NNAME_ALPHA":"Version \"0\", \"5\", \"19\""
}

[download]
Any pointers? Am I just looking at this from the wrong angle? Thanks for any help at all.

In reply to tidy up json via perl by Anonymous Monk

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