<?php

$file1 = '16.jpg';

$file2 = 'test.txt';

$file3 = '47.jpg';

$size = filesize($file1);

echo '文件大小为：'.$size;

echo "/n

转化为二进制 ...";

$content = file_get_contents($file1);

$content = bstr2bin($content);

$fp = fopen($file2, 'w');

fwrite($fp, $content);

fclose($fp);

$size2 = filesize($file2);

echo '转化成二进制后文件大小为：'.$size2;

$content = bin2bstr($content);

$fp = fopen($file3, 'w');

fwrite($fp, $content);

fclose($fp);

function bin2bstr($input)

// Convert a binary expression_r(e.g., "100111") into a binary-string

{

  if (!is_string($input)) return null; // Sanity check

  // Pack into a string

  $input = str_split($input, 4);

  $str = '';

  foreach ($input as $v)

  {

   $str .= base_convert($v, 2, 16);

  }

  $str =  pack('H*', $str);

  return $str;

}

function bstr2bin($input)

// Binary representation of a binary-string

{

  if (!is_string($input)) return null; // Sanity check

  // Unpack as a hexadecimal string

  $value = unpack('H*', $input);

  // Output binary representation

  $value = str_split($value[1], 1);

  $bin = '';

  foreach ($value as $v)

  {

   $b = str_pad(base_convert($v, 16, 2), 4, '0', STR_PAD_LEFT);

   $bin .= $b;

  }

  return $bin;

}

?>