Reverse hexdump without xxd


Login or Register for Dates, Times and to Reply

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Reverse hexdump without xxd
# 1  
Question Reverse hexdump without xxd

The "hexdump" command cannot perform reverse operation. On the other hand, the "xxd" command with -r option performs reverse hexdump, while the "xxd" command without -r performs the (forward) hexdump. An example of hexdump is to convert ABCD into 41 42 43 44. An example of reverse hexdump is to convert 41 42 43 44 back into ABCD.

The command "xxd" comes with Mac OS X. However, Linux may not come with "xxd". On a Linux that does not come with "xxd", how can reverse hexdump be achieved? Perhaps, vi editor?

Thanks in advance.
# 2  
xxd is available on most linux distros, it just may not be installed on yours, for whatever reason. It is definitely part of the standard install AFAIK.
try
Code:
find / -type f -name xxd

xxd(1): make hexdump/do reverse - Linux man page

Duplicating what it does is not simple, IMO, because it requires a parser, endian understanding, etc. You are far better off finding it on your box, or installing it.
# 3  
Assuming the values are space-delimited single bytes in hex:
Code:
$ cat hdump
41 42 43 44
45 46 47 48

echo 'ibase=16' | cat - hdump | tr ' ' \; | bc | awk '{printf("%c",$0)}'
ABCDEFGH

Regards,
Alister

Last edited by alister; 03-16-2010 at 11:31 PM..
# 4  
xxd is part of VIm. On OpenSuSE 10.3
Code:
> rpm -qf $(which xxd)
vim-base-7.1-44.2

So unless you're on an emacs/nano only system, you should have access to it. Note that *Ubuntu and Gentoo by default only ship nano, so you'll have to install VIm yourself.
Login or Register for Dates, Times and to Reply

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #100
Difficulty: Easy
Unix has built-in networking functions so that computers can easily exchange computer data.
True or False?

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Edit file hexadecimal with xxd

Hi all: I need edit a hexadecimal file. for example: 000d530: 0000 0000 0000 0000 0000 0000 493a 004f ............I:.O 000d540: 6374 2032 3820 3230 3135 2031 393a 3234 ct 28 2015 19:24 I need to cut the chain(black) and corresponding to hexadecimal from the chain at the end of file... (5 Replies)
Discussion started by: Rodrigo0461
5 Replies

2. Shell Programming and Scripting

How to perform a hexdump using dd from start point to end point?

hi, I would like to ask or is it possible to dump a hex using dd from starting point to end point just like the "xxd -s 512 -l 512 <bin file>" I know the redirect hexdump -C but i can't figure it out the combination options of dd. Hope someone can share their knowledge.. Thanks in... (3 Replies)
Discussion started by: jao_madn
3 Replies

3. Shell Programming and Scripting

reverse matching

Hello guys How can I use egrep to match word1 but not word2...word1. What I mean suppose that I have the following text, and my word1=pizza and word2=eat I hate to eat pizza because I ma eating it each day Pizza is good I like vegetarian and Italian Pizza eating healthy food is... (7 Replies)
Discussion started by: fdc2suxs
7 Replies

4. Shell Programming and Scripting

Puzzled with hexdump, hd and ln

How to create a symbolic link to a command with certain argument? When I man hexdump, it is said in the man page that "-C Canonical hex+ASCII display...Calling the command hd implies this option". Actually it is. hd equals to hexdump -C. And then I examined the ln command but find it is a... (5 Replies)
Discussion started by: vistastar
5 Replies

5. Shell Programming and Scripting

Reverse lookup

hey guys, can anybody help me out here on the following: grep '^\{1,3\}\.\{1,3\}\.\{1,3\}\.\{1,3\}$' ravi.txt mary.txt lisa.txt https://www.unix.com/images/misc/progress.gif i.e what i did was found ip addreses from different files and then i want... (1 Reply)
Discussion started by: ravis83
1 Replies

6. Shell Programming and Scripting

reverse sort

Hello, How do i sort a csv file. i should be sorting column1(varchar),column2*(varchar) in ascending and column4 in descending order(numeric datatype). I tried few combinations of sort, but doesn't seem to be getting the right result. sort -t "," -k 1 -k 2 -k 4nr file any help is... (3 Replies)
Discussion started by: markjason
3 Replies

7. Shell Programming and Scripting

Reverse FTP

Hi Everybody, I want to write a script in unix which will automatically FTP a .txt file from my client machine D: drive(Windows) That is I want to FTP a file from my PC to UNIX box but this should be done from UNIX box by a shell script. (i.e. I will invoke the script in UNIX and FTP will be... (4 Replies)
Discussion started by: ganesh123
4 Replies

8. Shell Programming and Scripting

reverse of basename

Hi, Can someone let me know how to find the reverse of the basename i.e i have /apps/tiv/pmon/xxxx.dat and I want /apps/tiv/pmon/ Thanks (7 Replies)
Discussion started by: braindrain
7 Replies

9. Shell Programming and Scripting

Reverse *

when I do $ ls z* List of all files begining with 'z'. But what if I want to do a reverse lookup. Just for interest sake ;) $ ls ztr should be same as $ ls ztr* $ ls zt* $ ls z* (2 Replies)
Discussion started by: azmathshaikh
2 Replies

Featured Tech Videos