[bash] ASCII to HEX and hex to ascii
 

What kind of command should I use to translate ascii to hex in a bash script ? (and hex back to ascii)

TIA

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do you mean something like this?The other direction (like an "ord(char)" function), is much less straightforward. Here are a couple of interesting solutions:

http://devworld.apple.com/documentat...section_3.html

And here's yet another possibility:... or, equivalently ...

Hi, yes something like that. Only but is that..
..this doesn't work in my box ;)
awk -W version
GNU Awk 3.1.5
it woold be good if it worked with words, not just single letters.

Cheers

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Edit: Thank you, I can use that hexdump, and that link is a nice one :)

Try the following instead (with Bash):
Edit: Sorry, I guess this is nonsense.

alternative in Python:

ascii to hex:

output:
'0x61'

hex to ascii
output:
'a'

... and I just learned that there's a package named uni2ascii which does the following:

Thanks guys, that uni2ascii is a good one, just compiled it and it does its job nicely.

There's a nice utility that comes with Vim called xxd. It is script-friendly, and (unlike od or hexdump) has the ability to go back and forth (with the revert option).

For example, you could have something like:
Where there are three fields you can access in awk. $1 is the offset (in hex), $2 is the two-digit hex representation of a byte, and $3 is the ASCII representation of the byte (or just a period for nonprintable characters).

For going back, just do something like:
The only formatting restrictions on the input is that single bytes appear together as two-digit numbers. It doesn't care about formatting or whitespace (the -p is for plain).

I guess xxd's not as portable as hexdump or od, but it is probably more portable than uni2ascii (i.e., is more likely to be found installed on a *nix machine than uni2ascii).

Thats true, but I'm not that concerned about portability, (I'm using slax based Back|Track and adding modules is easy) and I'm not doing anything really important, just learning to write my own snort rules and I was getting tired to visit online hex translators ;)

But anyways, that ascii2hex is working nicely with my script so thanks again.

:)

Another awk alternative with more than one character
 

gives

What if your string is:
48656C6C6F2074686572652021

And you don't have perl, python, xxd or uni2ascii?
And you are not allowed to install it.

How can you convert it?

Or course I could always write a loop and read it in pairs:

Hex to ascii is dead easy; bash can do it internally, if they're properly formatted. Just use "echo -e", printf's %b format token, or the $'..' quoting form. See the sections on QUOTING and the echo built-in in the bash man page for full details on what these options can expand.

So in post #10 above, the awk command is actually completely superfluous. The characters are converted by echo before they even reach it.

As for the reverse direction, there's no built-in way to do it, so see the above. I've also used uniname before to get the hex codes of a string of characters.

Edit: Example use for the string in #9:

I used a '(..)' subshell in order to keep the IFS setting local. It's needed in order to print the '*' expansion without spaces between each entry. Changing '*' to '@' would print every character on a separate line.

You guys with awk are silly... your awk is not doing anything at all. Sorry to point that out. :P

Works fine for me with both bash and sh. It looks to me like you have an outdated version of awk that doesn't support "$_", but I have no experience with FreeBSD. I'm running GNU awk 3.1.8