json_pretty_print.pl

# Pretty print input JSON-formatted single lines into pretty huge array of JSON objects.

use strict;
use warnings;
use JSON;

our $json_output_config = { pretty => 1, utf8 => 0, ascii => 1, canonical => 1 };

#use IO::Handle qw();

die "Usage: script input.lines.json output.pretty.json" unless scalar @ARGV == 2;

open my $f, "<$ARGV[0]" or die "Can't open input for read.";
binmode $f;

my @all;

my $line = 0;

while (<$f>) {
    next if /^\s*$/;

    printf STDERR ".";

    push @all, from_json($_);

    ++$line;
}

close $f;

open my $g, ">:encoding(utf-8)","$ARGV[1]" or die "Can't open output for write.";
print $g chr(0xFEFF) if $json_output_config->{utf8}; # BOM

print $g to_json(\@all, $json_output_config);

close $g;