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bitmapdd

Creates a bitmap from a file (or device). It’s mainly used for creating a usage map of input but it can also do conversions.

Examples:

Blocksize Input (hexadecimal) Output (binary)
1 00 31 00 40 A0 FF 02 00 01011110
1* 30 31 30 30 31 30 30 31 01001001
2 16 00 72 B0 00 00 00 00 1100
4 00 00 00 00 00 A3 00 F7 01

* With an additional "-null 48" parameter (48 in decimal is 30 in hexadecimal).

Usage

bitmapdd [options]

Options:

  • --null NUM Character code of null (default: 0). For example you should set this to 48 when you need to convert a text file consists of 0/1 characters to a binary file where each character is mapped to a bit.
  • --bs NUM Block size of input file (default: 512). If all bytes of a block is 0 than it will mapped to 0 bit, else it will mapped to 1 bit.
  • --count NUM Count of blocks to process (default: till end of input).
  • --if FILE Specifies the input file (default: stdin).
  • --of FILE Specifies the output file (default: stdout)
  • --help Prints usage information.
  • --version Prints version information.

Program supports stdout/stdin redirections, so the following should work: cat /dev/sda | bitmapdd > output.dat

You can get progress information by sending a SIGUSR1 signal to the process: kill -SIGUSR1 pid (where pid is the process identifier)

Scenerio 1

You have a file which consists of blocks of data. If a block is full of zeros than it’s free, otherwise it’s used. You want to make a bitmap from it where a bit in the file is 0 if the corresponding block is zero, otherwise it’s 1.

For example with block size set to 4:

bitmapdd --bs 4 --if input.dat --of output.dat

00 00 00 00 | 34 00 56 00 | 00 00 00 00 | F3 11 23 00
         \            |       |            /
           \          |       |          /
             \        |       |        /
               0      1       0      1

Scenerio 2

Converting a text of zeros and ones to a binary file where every bit corresponds to one character in the original file.

bitmapdd --bs 1 --null 48 --if usagemap.txt --of usagemap.dat

Note: null byte has been set to 48 which is the code of character “0″ in the ASCII character table.

usagemap.txt contains text:

001100000100000001000001

usagemap.dat will contain text:

0@A
Character Decimal code Binary code
0 48 00110000
@ 64 01000000
A 65 01000001

Build

Program should build on any UNIX like operation system with a standard C compiler and make utility.

To compile:

make

To compile without signal handling:

make CFLAGS='-DNOSIGNAL'

To run:

./bin/bitmapdd

(however it is not recommended to call this way because it will wait for input from stdin)

To clean:

make clean

Author

Written by Andras Majdan.

License: GNU General Public License Version 3

Report bugs to [email protected]

See also

bitmap2pbm - Creates a P4 type PBM image from a binary file.

fat2bitmap - Creates a bitmap from FAT file system free/used clusters.