1#!/usr/bin/perl -w
2
3use strict;
4use warnings;
5use Getopt::Long;
6use Fcntl;
7
8my $verbosity = 0;
9my $blksize = 512;
10my $byte = 0;
11
12my %opts = (
13  'verbose|v+' => sub { $verbosity++; },
14  'quiet|q+' => sub { $verbosity--; },
15  'blksize|s=o' => sub { $blksize = $_[1]; },
16  'byte|b=o' => sub { $byte = $_[1]; },
17);
18
19Getopt::Long::Configure ( 'bundling', 'auto_abbrev' );
20GetOptions ( %opts ) or die "Could not parse command-line options\n";
21
22while ( my $filename = shift ) {
23  die "$filename is not a file\n" unless -f $filename;
24  my $oldsize = -s $filename;
25  my $padsize = ( ( -$oldsize ) % $blksize );
26  my $newsize = ( $oldsize + $padsize );
27  next unless $padsize;
28  if ( $verbosity >= 1 ) {
29      printf "Padding %s from %d to %d bytes with %d x 0x%02x\n",
30	     $filename, $oldsize, $newsize, $padsize, $byte;
31  }
32  if ( $byte ) {
33    sysopen ( my $fh, $filename, ( O_WRONLY | O_APPEND ) )
34	or die "Could not open $filename for appending: $!\n";
35    syswrite $fh, ( chr ( $byte ) x $padsize )
36	or die "Could not append to $filename: $!\n";
37    close ( $fh );
38  } else {
39    truncate $filename, $newsize
40	or die "Could not resize $filename: $!\n";
41  }
42  die "Failed to pad $filename\n"
43      unless ( ( ( -s $filename ) % $blksize ) == 0 );
44}
45