#!/usr/bin/env perl

# subdivide.pl - given a few configurations, divide a directory into many smaller ones
# see: https://stackoverflow.com/questions/36511098/split-large-directory-into-subdirectories


# configure
my $BASE      = "json";
my $ROOT      = './jsons';
my $LIMIT     = 10000;
my $i         = 0;
my $directory = '';

# require
use strict;
use File::Copy;

# open the directory and process each file
opendir( my $handle, $BASE ) or die( "Can't open $BASE: $!\n");
while ( my $file = readdir( $handle ) ) {
	
	# sanity check
	next if $file !~ /json$/;
	warn( "  file: $file\n" );

	# check for new directory needed
	if ( $i % $LIMIT == 0 ) {

		 # create a new directory
		 $directory = sprintf( "%s/json_%03d", $ROOT, ( int( $i/$LIMIT ) + 1 ) );
		 warn( "  directory: $directory\n" );
		 mkdir( $directory ) or warn( "Can't make directory $directory: $!\n" );
 
	}

	# copy the given file to the new directory
	copy( "$BASE/$file", "$directory/$file" ) or do {

		warn("Can't move $file into $directory: $!\n");
		next;

	 };

	# increment
	$i++;

}