Dostortugas

This is an old revision of the document!

if you are the author of this script please let me know (I forgot to link you down)

randfs /mnt/file

#!/usr/bin/perl
 
use strict;
use warnings;
use IO::File;
 
$|=1;
 
my $file;
 
sub randomString(){
	my $fetch=(int(rand(512))+512)*20480;
	my $data='';
	my $packet;
	my $fh=new IO::File('/dev/urandom','r')
		|| die("Unable to open /dev/urandom: $!\n");
	binmode($fh);
	while(length($data) < $fetch){
		printf("\rGenerating %d bytes urandom string... %d%%",$fetch,(length($data)*100/$fetch));
		read($fh,$packet,8192);
		$data.=$packet;
	}
	$fh->close();
	printf("\rGenerating %d bytes urandom string... done\n",$fetch);
	return($data);
}
 
sub fillDisk($){
	my $string=shift;
	my $written=0;
	my $size=length($string);
	my $started=time;
	my $mbytes;
	$SIG{TERM}=$SIG{INT}=sub{
			print("\n");
			removeFile();
			exit(1);
		};
	my $fh=new IO::File($file,'w')
		|| die("Unable to open $file: $!\n");
	binmode($fh);
	while(print($fh $string)){
		$written+=$size;
		$mbytes=$written/1048576;
		printf("\rWriting growing file to disk... %d MB (%d MB/s)   ",$mbytes,($mbytes/((time-$started)||1)));
	}
	$fh->close();
	print("\n");
}
 
sub syncDisk(){
	print('Writing cached data to disk... ');
	system('/bin/sync');
	print("done\n");
}
 
sub removeFile(){
	print('Removing the growing file from disk... ');
	unlink($file);
	system('/bin/sync');
	print("done\n");
}
 
sub showUsage(){
print(<<__EOF);
This programm will generate a urandom string of 10 to 20 MBytes,
repeatedly write this into the given file until writing becomes impossible
and remove the file from disk.
 
The given file must NOT exist!
 
Usage: $0 <filename>
 
__EOF
	exit(1);
}
 
sub main(){
	$file=$ARGV[0];
	print("Randomize Free Space, (C)2006 Veit Wahlich <cru at zodia dot de>\n\n");
	unless(defined($file) && $file=~/^[^\-]/ && not(-e $file)){
		showUsage();
	}
	fillDisk(randomString());
	syncDisk();
	removeFile();
	exit(0);
}
 
main();
1;