PHP Bit String: Manipulate strings of sequences of binary digits

Recommend this page to a friend!

Download .zip

Info

Example

View files (5)

Download .zip

Reputation

Support forum

Blog

Links

Ratings				Unique User Downloads		Download Rankings
Not enough user ratings				Total: 101		All time: 9,717 This week: 148

Version		License		PHP version		Categories
`bitstring` 1.0		BSD License		5.6		PHP 5, Text processing, Data types

Description

Author

Christian Vigh

This class can manipulate strings of sequences of binary digits.

It can take a string of data or binary digits and create an internal array of data.

The class can convert the bits to hexadecimal, to binary data, or a string of binary digits.

It also provide an iterator interface so it can be treated as an array of bits using the regular array manipulation functions.

Christian Vigh

Performance

Level

Name:	Christian Vigh `<contact>`
Classes:	32 packages by Christian Vigh
Country:	France
Age:	57
All time rank:	138	10 in France
Week rank:	10	1 in France

Level 6

Innovation award

Nominee: 20x

Winner: 3x

Example


<?php


    /*************************************************************************************************





        This example demonstrates the use of the BitString and BitStringIterator classes on a


        simple example string, "ABCDEF", which will be considered as a string of bits.





     *************************************************************************************************/





    require_once ( 'BitString.phpclass' ) ;





    if  ( php_sapi_name ( )  !=  'cli' )


        echo '<pre>' ;





    // getbits -


    //    This function simply outputs bits from the specified value, up to $count.


    function  getbits ( $value, $count )


       {


        $result        =  '' ;





        for  ( $i = 0 ; $i  <  $count ; $i ++, $value >>= 1 )


            $result        .=  ( $value  &  1 ) ?  '1' : '0' ;





        return ( $result ) ;


        }





    // Our example string


    $data    =  "ABCDEF" ;





    // Create a bit string from it


    $bs    =  new BitString ( $data ) ;





    // Try the ToHex() and ToBin() functions. Note that ToBin (0) will print the bits in exactly the same order


    // as they are stored (least significant bit first), while ToBin(1) will print them in the order they are 


    // printed by ToHex()


    echo "ToHex()                : "  ; print_r ( $bs -> ToHex ( ) )   ; echo "\n" ;


    echo "ToBin(1)               : " ; print_r ( $bs -> ToBin ( 1 ) ) ; echo "\n" ;


    echo "ToBin(0)               : " ; print_r ( $bs -> ToBin ( 0 ) ) ; echo "\n" ;





    // Use the ArrayAccess interface to retrieve and display each individual bit


    echo "Bit per bit (for)      : " ;





    for ( $i = 0 ; $i < count ( $bs ) ; $i ++ )


        echo $bs [$i] ;





    // Use the Iterator interface to display each individual bit


    echo "\nBit per bit (foreach)  : " ;





    foreach ( $bs  as  $bit )


        echo $bit ;





    // Now, use the BitString::GetBits() function to display bits by group of x bits, from 1 to 32.


    // Note that the getbits() function defined here will add trailing zeroes for bit counts that are


    // not a denominator of the machine's word size - this is not a bug, this inconvenience was aimed


    // at making this example simpler


    for  ( $bit_count = 1 ; $bit_count  <=  32 ; $bit_count ++ )


       {


        echo sprintf ( "\nTaking by %2d bits      : ", $bit_count ) ;


        


        for  ( $i = 0 ; $i  <  count ( $bs ) ; $i += $bit_count )


           {


            $value        =  $bs -> GetBits ( $i, $bit_count ) ;





            if  ( $value  ===  false )


                output ( "FALSE for offset $i, count $bit_count" ) ;





            echo getbits ( $value, $bit_count ) ;


            }


        }





    // Now use a BitStringIterator object : extract bits from the bit string by groups of


    // 3 components having 8 bits each. It should display the hexadecimal translation of


    // "ABCDEF" which is : "414243444546"


    echo "\nBitStringIterator(8,3) : " ;





    foreach  ( new BitStringIterator ( $bs, 8, 3 )  as  $values ) 


       {


        foreach  ( $values  as  $value )


            echo ( sprintf ( "%02X", $value ) ) ;


        }

Files

File	Role	Description
`BitString.phpclass`	Class	Class source
`example.php`	Example	Example script
`LICENSE`	Lic.	License text
`NOTICE`	Data	Auxiliary data
`README.md`	Doc.	Documentation