php怎样将二进制流存到文件中

$str  = 0x8000;

echo  $str2  =  base_convert ( $str , 16, 2);
echo  '' ;
echo  base_convert ( $str2 , 2, 16);
[code]

字符串 文件等 可以考虑用 pack 和 unpack 转化成二进制

[code=PHP]
$file1  =  'F:/46.gif' ;            //随便拷一个图片作为测试用
$file2  =  'F:/test.txt' ;          //生成的二进制流保存在这个文件里
$file3  =  'F:/47.gif' ;            //由二进制流还原成的文件

$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 (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 ;
}