Perl assembly generator

21 Oct 2011 I wrote a little perl script that receives input and creates an x86 assembly program. This program put all data on stack and then print it using printf c function. Useless but cool

#!/usr/bin/perl

use warnings;
use strict;

undef $/;
my $input = <>

$input = unpack("H*", $input);
my @integers;

while (length($input) > 8) {
 my $str = substr($input, 0, 8);
 $str =~ s/(.{2})(.{2})(.{2})(.{2})/$4$3$2$1/;
 push(@integers, ("0x".$str));
 $input = substr($input, 8);
}

my $buf = "";
while (length($input) > 0) {
 $buf .= substr($input, -2);
 $input = substr($input, 0, -2);
}

push(@integers, sprintf("0x%08x", hex($buf)));
my $stck_deep = ($#integers + 1) * 4;

print <<EOS
        .section        .text.startup,"ax",\@progbits
        .globl  main
        .type   main, \@function
main:
        pushl   %ebp
        movl    %esp, %ebp

 subl \$$stck_deep, %esp

 movl \$$integers[0], (%esp)
EOS
;

for my $i (1 .. $#integers) {
 printf("\tmovl \$%s, %d(%%esp)\n", $integers[$i], $i * 4); 
} 

print <<EOS
 movl \$0x0, $stck_deep(%esp)
 
 pushl %esp
 call printf
 popl %eax

 addl \$$stck_deep, %esp


 xorl %eax, %eax
 leave
 ret
EOS

;

Here is a try:
https://ideone.com/cuvXe
https://ideone.com/2oA9q
[]'s