#!/bin/bash
#
# BFM.sh
# A very simple DEMO Binary File Manipulation shell code issued entirely as Public Domain.
#
# Apologies for any typos...
#
# This is a DEMO to show how to generate binaryfiles in the shell.
# I need this facility for a kids project I am doing. It will be posted onto here in
# the not too distant future...
#
# To run, ensure the script is executable and from a terminal type:-
#
# *****$ /absolute/path/to/BFM.sh<CR>
#
# And away you go...
#
# Many thanks to MartyBartFast of the Linux Format forums for reminding me of the backticks... ;o)
#
# Written so that kids and newbies can understand what is going on...
#
# $VER: BFM.sh_Version_0.00.10_Public_Domain_2013_B.walker_G0LCU.
#
# Enjoy finding simple solutions to often very difficult problems...
# These two files WILL be generated inside YOUR default /directory/drawer/folder/...
# Zero them as a starter JUST for this DEMO...
> SomeBinaryFile.dat
> MyBinaryFile.dat
# This loop is to give a usable 256 byte binary file only from 0x00 to 0xFF continuous...
clear
for character in {0..255}
do
# Note:- The backticks and the four escape characters are required...
char=`printf '\\\\x'"%02x" $character`
printf "$char" >> SomeBinaryfile.dat
done
# Do a hexadecimal dump to prove the file is binary and 256 bytes in size...
printf "\nOffset. Hexadecimal Dump. ASCII Dump.\n"
hexdump -C SomeBinaryFile.dat
# Now this EXAMPLE loop is the working loop. The three variables set the "start", (_offset_), of where you want
# your file to start, the "jump" between each _sample_ and the last_byte_limit to where you want to finish...
# IMPORTANT!!! There is NO error detection or correction in the code as it is a DEMO so don't come back and
# say that you can crash it, e.g. setting the "last_byte_limit" to -1 for example...
# Also although I am using a "for" loop for this DEMO you could select a single byte manually and code accordingly...
#
# The _variables_ for this DEMO. The jump is set to every seventh byte for this DEMO.
start_offset=0
jump=1
last_byte_limit=400
# _hexdump_ is used to select the byte(s) according to this DEMO "for" loop...
for subscript in $( seq $start_offset $jump $last_byte_limit )
do
number=`hexdump -n1 -s$subscript -v -e '1/1 "%u"' SomeBinaryFile.dat`
# number=`hexdump -n1 -s$subscript -v -e '1/1 "%u"' arduino.dat`
char=`printf '\\\\x'"%02x" $number`
printf "$char" >> MyBinaryFile.dat
done
# Now display it...
printf "\nOffset. Hexadecimal Dump. ASCII Dump.\n"
hexdump -C MyBinaryFile.dat
# A terminal window dump of what should occur...
#
# Offset. Hexadecimal Dump. ASCII Dump.
# 00000000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f |................|
# 00000010 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f |................|
# 00000020 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f | !"#$%&'()*+,-./|
# 00000030 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f |0123456789:;<=>?|
# 00000040 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f |@ABCDEFGHIJKLMNO|
# 00000050 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f |PQRSTUVWXYZ[\]^_|
# 00000060 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f |`abcdefghijklmno|
# 00000070 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f |pqrstuvwxyz{|}~.|
# 00000080 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f |................|
# 00000090 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f |................|
# 000000a0 a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af |................|
# 000000b0 b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf |................|
# 000000c0 c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf |................|
# 000000d0 d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df |................|
# 000000e0 e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef |................|
# 000000f0 f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff |................|
# 00000100
#
# Offset. Hexadecimal Dump. ASCII Dump.
# 00000000 04 0b 12 19 20 27 2e 35 3c 43 4a 51 58 5f 66 6d |.... '.5<CJQX_fm|
# 00000010 74 7b 82 89 90 97 9e a5 ac b3 ba c1 c8 |t{...........|
# 0000001d
# Barrys-MacBook-Pro:~ barrywalker$
#
# BFM.sh DEMO end...
# Enjoy finding simple solutions to often very difficult problems...
