1
Files
rle/unrle.pl
2018-09-23 14:39:28 +03:00

70 lines
1.6 KiB
Perl

#!/usr/bin/perl
use strict;
use warnings "all";
use Fcntl;
my $fname = undef;
if(defined($ARGV[0])){
if($ARGV[0] eq "--help"){
syswrite STDOUT, "Usage: $0 <filename>\n";
syswrite STDOUT, "or pipe data thrugh $0's STDIN to $0 STDOUT\n";
exit 0;
}
exit unless ($ARGV[0] =~ /\.rle$/);
$fname = $ARGV[0];
$fname = substr($fname, 0, -4);
}
my $byte = '';
my $dbyte = '';
my $block_size = 65536;
if (defined($fname)){
sysopen(STDIN, "$fname.rle", O_RDONLY) or die "Can not open file $fname!\n";
sysopen(STDOUT, $fname, O_WRONLY|O_TRUNC|O_CREAT) or die "Can not open file $fname.rle!\n";
}
binmode(STDIN);
binmode(STDOUT);
my $output_buf_byte_counter = 0;
my $output_buf = '';
my $input_buf ='';
while ( 1 ) {
my $read_bytes = sysread(STDIN, $input_buf, $block_size);
last unless(defined($read_bytes));
last if($read_bytes == 0);
my $i = 0;
for ( $i = 0; $i < $read_bytes; $i++ ) {
$dbyte = substr( $input_buf, $i, 1);
last unless(defined($dbyte));
$i++;
$byte = substr( $input_buf, $i, 1);
last unless(defined($byte));
for(my $i = 0; $i < ord($dbyte); $i++){
if ($output_buf_byte_counter == $block_size){
syswrite STDOUT, $output_buf || die "Cannot write output stream!\n";
$output_buf = '';
$output_buf_byte_counter = 0;
}else{
$output_buf_byte_counter++;
}
$output_buf .= $byte;
}
}
undef $i;
undef $read_bytes;
}
close(STDIN);
syswrite STDOUT, $output_buf || die "Cannot write output stream!\n";
close(STDOUT);
undef $fname;
undef $byte;
undef $dbyte;
undef $block_size;
undef $output_buf_byte_counter;
undef $output_buf;
undef $input_buf;