Transform hexadecimal information to binary using a Linux command

Question

I have this binary file on my Linux system...

 udit@udit-Dabba ~ $ cat file.enc
 Salted__s�bO��<0�F���Jw!���]�:`C�LKȆ�l

Using the hexdump command, I see its information like this:

 udit@udit-Dabba ~ $ hexdump -C file.enc
 00000000  53 61 6c 74 65 64 5f 5f  1b 73 a1 62 4f 15 be f6  |Salted__.s.bO...|
 00000010  3c 30 cc 46 ee 10 13 11  84 bf 4a 77 21 a4 84 99  |<0.F......Jw!...|
 00000020  0e 5d ef 11 18 3a 60 43  a0 4c 4b 1e c8 86 e6 6c  |.]...:`C.LK....l|
 00000030

Now I am given a file on some other system whose contents are like this:

 53 61 6c 74 65 64 5f 5f  1b 73 a1 62 4f 15 be f6
 3c 30 cc 46 ee 10 13 11  84 bf 4a 77 21 a4 84 99
 0e 5d ef 11 18 3a 60 43  a0 4c 4b 1e c8 86 e6 6c

And I need to find out that same exact binary information from this hexdump.

How can I proceed for that?

If there isn't any switch for that then C code will also work fine.

(But a Linux command with some switch is preferable)

Limitation:

The binary information in the file is output of an encryption algorithm, so contents should exactly match...

Dreary

Have a look at xxd – Weight

@Weight Thnx It helped I knew about -r and not -p and needed it soon ... so posted the question – Dreary

About the same subject, see also: https://mcmap.net/q/117168/-how-to-create-a-hex-dump-of-file-containing-only-the-hex-characters-without-spaces-in-bash – Hemstitch

Answer 1

As @user786653 suggested, use the xxd(1) program:

xxd -r -p input.txt output.bin

Queri

to add use echo "hex" | xxd -r -p - to take input from piped standard out – Fizzy

Can also be used to get binary hashes - like echo something | sha256sum | xxd -r -p - – Encyst

To explain the flags: explainshell.com/explain?cmd=xxd+-r+-p – Notecase

Note that xxd uses very old fashioned argument processing, so all of the following behave differently: xxd -rp xxd -pr xxd -r -p. Only the last of the three works for this use case. – Subaudition

@Fizzy no need to do that because the man page says that If no infile is given, standard input is read. – Hagen