9 GetOptions ("h|help" => sub { usage (0); })
11 usage (1) if @ARGV != 2;
13 my ($disk, $mb) = @ARGV;
14 die "$disk: already exists\n" if -e $disk;
15 die "\"$mb\" is not a valid size in megabytes\n"
16 if $mb <= 0 || $mb > 1024 || $mb !~ /^\d+(\.\d+)?|\.\d+/;
18 my ($cyl_cnt) = ceil ($mb * 2);
19 my ($cyl_bytes) = 512 * 16 * 63;
20 my ($bytes) = $cyl_bytes * $cyl_cnt;
22 open (DISK, '>', $disk) or die "$disk: create: $!\n";
23 sysseek (DISK, $bytes - 1, SEEK_SET) or die "$disk: seek: $!\n";
24 syswrite (DISK, "\0", 1) == 1 or die "$disk: write: $!\n";
25 close (DISK) or die "$disk: close: $!\n";
29 pintos-mkdisk, a utility for creating Pintos virtual disks
30 Usage: pintos DISKFILE MB
31 where DISKFILE is the file to use for the disk
32 and MB is the disk size in (approximate) megabytes.
34 -h, --help Display this help message.