Shell: How to read the bytes of a binary file and print as hexadecimal?

Question

In shell, how can I read the bytes of a binary file I have, and print the output as hexadecimal numbers?

http://stackoverflow.com/questions/2003803/show-hexadecimal-numbers-of-a-file/2004276#2004276 — Ciro Santilli OurBigBook.com, Sep 04 '15 at 08:20

score 75 · Accepted Answer · answered Apr 07 '11 at 14:11

75

Use hexdump(1)

$ hexdump -x /usr/bin/hexdump 
0000000    feca    beba    0000    0300    0001    0700    0080    0300
0000010    0000    0010    0000    5080    0000    0c00    0000    0700
0000020    0000    0300    0000    00a0    0000    b06f    0000    0c00
0000030    0000    1200    0000    0a00    0100    0010    0000    107c
0000040    0000    0c00    0000    0000    0000    0000    0000    0000
0000050    0000    0000    0000    0000    0000    0000    0000    0000

...

answered Apr 07 '11 at 14:11

pdo

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Also check out `od`. There is also a vi-style hex editor called `hexer`. – LawrenceC Apr 07 '11 at 14:47
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I like the output of "hexdump -C file" better. xxd is also a nice tool. – Kambus Apr 07 '11 at 17:09
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show in bash hexa format `hexdump -e '"\\\x" /1 "%02x"' filename` – Aquarius Power Nov 20 '14 at 16:10
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For information, the first column is the hexadecimal offset of the bytes, the rest of the line is 8 sets of two-byte displays, i.e. 16 bytes, which is why the second line starts with an offset of `10`, which is 16 in hexadecimal. The two-byte representation depends on the [endianness](https://en.wikipedia.org/wiki/Endianness) of the system. Type `man hexdump` for the full details. – miguelmorin Dec 07 '18 at 13:23
my above trick is bad, hexdump will output '*\n' for any repeating bytes. I am using this instead: `... |od -A n -t x1 |tr -d ' \n'` – Aquarius Power Aug 20 '23 at 23:50

user unknown · Answer 2 · 2017-04-26T15:00:58.310

42

Another option is od:

od -t x1 FILE

or

od -x FILE

od has many options for finetuning.

edited Apr 26 '17 at 15:00

answered Apr 07 '11 at 15:46

user unknown

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Most people would find `od -t x1` as preferred format I guess. – alex Apr 07 '11 at 16:43
For the line `od -t test` I got `od: invalid character 't' in type string 'test'` – The Student Apr 11 '11 at 13:52
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It worked with `--t` – The Student Apr 11 '11 at 13:53
@Tom: Maybe a different Unix/Linux flavor? My od is: `od --version od (GNU coreutils) 7.4` – user unknown Apr 11 '11 at 15:01
If it can help somebody else, I wanted to have the last 4 bytes in hex of a binary file. Here is what I did that works. od -A n -t x1 -w1 -v myFile.bin | tail -n 4 | sed 's/ //g' | paste -sd '' – mgouin Feb 17 '22 at 18:53
`tail -c 4 BINFILE` might be the more easy way, to isolate 4 bytes. You may then format the output with `od` or something else to your needs. – user unknown Feb 18 '22 at 01:46

Mikel · Answer 3 · 2011-04-08T02:41:33.227

While we're on od and hexdump, two more similar tools:

hd (from bsdmainutils)
xxd (part of Vim)

Sample output:

$ hd /usr/bin/od | head
00000000  7f 45 4c 46 01 01 01 00  00 00 00 00 00 00 00 00  |.ELF............|
00000010  02 00 03 00 01 00 00 00  20 8e 04 08 34 00 00 00  |........ ...4...|
00000020  a4 a2 00 00 00 00 00 00  34 00 20 00 08 00 28 00  |........4. ...(.|
00000030  1b 00 1a 00 06 00 00 00  34 00 00 00 34 80 04 08  |........4...4...|
00000040  34 80 04 08 00 01 00 00  00 01 00 00 05 00 00 00  |4...............|
00000050  04 00 00 00 03 00 00 00  34 01 00 00 34 81 04 08  |........4...4...|
00000060  34 81 04 08 13 00 00 00  13 00 00 00 04 00 00 00  |4...............|
00000070  01 00 00 00 01 00 00 00  00 00 00 00 00 80 04 08  |................|
00000080  00 80 04 08 c4 9d 00 00  c4 9d 00 00 05 00 00 00  |................|
00000090  00 10 00 00 01 00 00 00  00 a0 00 00 00 20 05 08  |............. ..|

$ xxd /usr/bin/od | head
0000000: 7f45 4c46 0101 0100 0000 0000 0000 0000  .ELF............
0000010: 0200 0300 0100 0000 208e 0408 3400 0000  ........ ...4...
0000020: a4a2 0000 0000 0000 3400 2000 0800 2800  ........4. ...(.
0000030: 1b00 1a00 0600 0000 3400 0000 3480 0408  ........4...4...
0000040: 3480 0408 0001 0000 0001 0000 0500 0000  4...............
0000050: 0400 0000 0300 0000 3401 0000 3481 0408  ........4...4...
0000060: 3481 0408 1300 0000 1300 0000 0400 0000  4...............
0000070: 0100 0000 0100 0000 0000 0000 0080 0408  ................
0000080: 0080 0408 c49d 0000 c49d 0000 0500 0000  ................
0000090: 0010 0000 0100 0000 00a0 0000 0020 0508  ............. ..

Or, if you want to read the bytes one at a time and print them in your own format, try something like:

while read -n 1 byte; do
    ord=$(printf "%b" "${byte:-\000}" |
          od -t x1 |
          { read offset hex; echo $hex; })
    echo "$ord"
done </usr/bin/od

Sample output:

unlike the other, xxd is also able to revert the modification. With that, it is possible to alter a binary file with shell. — Offirmo, Jun 11 '12 at 16:31
Your `while` loop doesn't work for backslash and newline characters (and in bash (as opposed to ksh93) for blank characters), nor will it work properly in utf8 locales for bytes with the 8th bit set. Also, you don't need "od" there, you can use `printf '%02x\n' "'$byte"` — Stéphane Chazelas, Oct 15 '12 at 20:13
Note: `offset` is merely a sort of "dummy variable" here; it has no practical use. It is just used as a placeholder to get to `hex`. This is what sometimes affects readability in a negative way with `read`: variables coming out of the blue. — syntaxerror, Dec 02 '14 at 00:01
Perhaps. But in this case, the scope of `$offset` is limited by the subshell, so I don't see it as a problem. — Mikel, Dec 02 '14 at 03:44

score 8 · Answer 4 · edited Oct 15 '12 at 16:52

8

My two cents:

tail -f streamfile | hexdump -C

I like this because you are tailing a currently buffering file while being able to see the hexdump live. Don't forget that EVERYTHING in Unix is a file and we can easily chain commands like tail and hexdump to solve a wide variety of problems.

edited Oct 15 '12 at 16:52

jasonwryan

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answered Oct 15 '12 at 14:33

MacGyverQue

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tested with `for((i=0;i<100;i++));do echo $i >>tst2.bin;sleep 1;done&` it works well for monitoring thx :) – Aquarius Power Nov 20 '14 at 15:56

score 5 · Answer 5 · answered Apr 08 '11 at 14:42

5

mc

The midnight commander is another option. I don't know whether it is available for all unix flavors. You might need to download it first.
F3 F4 to view in internal editor/ in hex mode.

answered Apr 08 '11 at 14:42

user unknown

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Sergio K · Answer 6 · 2019-03-25T19:47:10.573

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I use od with c and x1, when I need to search for text inside the binary file:

$ echo "Some text..." | od -t c -t x1
0000000   S   o   m   e       t   e   x   t   .   .   .  \n
         53  6f  6d  65  20  74  65  78  74  2e  2e  2e  0a
0000015

edited Mar 25 '19 at 19:47

answered Mar 25 '19 at 19:37

Sergio K

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score 1 · Answer 7 · answered Oct 28 '20 at 17:37

If the data you're viewing is mostly text with occasional binary, you might find the -v option to cat(1) convenient:

$ printf 'here is\x00\x01some text\x15\x16with the odd bit\x80\x81of binary mixed in' | cat -v
here is^@^Asome text^U^Vwith the odd bitM-^@M-^Aof binary mixed in

Non-printing bytes ≤ 0x7f are displayed with control-character notation. Bytes ≥ 0x80 are prefixed by M-.

This isn't reversible since M- itself doesn't appear to be escaped. Nonetheless, it can be easier to read than the full canonical hex dump format given by hd(1) and other tools.

Shell: How to read the bytes of a binary file and print as hexadecimal?

7 Answers7