I need a substitute for ghex - regex

Question

When i install Sublime Text 2 in my system(Debian) i need to use ghex to find the address 0x590ADC with Edit->Goto Byte. After that, i need replace the number 33 for 32. All this to solve a problem with backspace key.
So, i would like to know if there is other way to do that without using ghex, i would like to do that using command line(sed maybe) because i use a bashscript to install all my system, including softwares like Sublime Text 2.
Bellow, a sed command that replaces all occurrences of 33 42 and replaces for 32 42.
sed 's/\x33\x42/\x32\x42/g' sublime_text
I need something like above, but in a specific address, and 42 is not necessary anymore.
Thank you!

Answer 1

Using bash and dd:
#!/bin/bash
function replace {
[[ $# -eq 4 && -f $1 ]] || return 1
local FILE=$1 ADDRESS=$2 EXPR=$3 LENGTH=$4
local BLOCK_SIZE=512
local BLOCKS=$(( ADDRESS / BLOCK_SIZE ))
local REM=$(( ADDRESS - (BLOCKS * BLOCK_SIZE) ))
{
[[ BLOCKS -gt 0 ]] && dd bs="$BLOCK_SIZE" count="$BLOCKS" status=none
[[ REM -gt 0 ]] && dd bs=1 count="$REM" status=none
printf "$EXPR"
dd bs=1 count="$LENGTH" of=/dev/null status=none
dd bs="$BLOCK_SIZE" status=none
} < "$FILE"
}
Example data (hexdump -C format):
00000000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f |................|
00000010 10 11 12 13 14 |.....|
Test:
replace data.bin 10 '\xFF\xFF' 2
Output:
00000000 00 01 02 03 04 05 06 07 08 09 ff ff 0c 0d 0e 0f |................|
00000010 10 11 12 13 14 |.....|

Answer 2

This pattern match 33 and 33 42 also
~s/\x33(\x42)?/\x32$1/g

Answer 3

sed doesn't have byte addressing, but it's easy enough to do this with standard tools.
( cut -b1-5835484 file; printf "%c" 50; cut -b5835486- file )>newfile
Given enough unique context, it is possible to find an expression which probably only matches once in the file (but in the pessimal case, you need the entire file as context) so you can do something like
sed 's/\(\x01\xf3\x29\x02\)\x33\(\x42\x29\xea\x44)/\1\x32\2/' file >newfile
There are also programmable hex editors which allow you to do this with a simple sed-like language with byte addressing. Or if you have a hexdump program which reads its own input to reconstruct a new file, do something like
hexdump file |
sed 's/\(^0x0x590AD0 .. .. .. .. .. .. .. .. .. .. .. .. \)33/\132/' |
hexdump -v >newfile