Linux shell scripting: hex number to binary string

Question

I am looking for some easy way in shell script for converting hex number into sequence of 0 and 1 characters.

Example:

5F -> "01011111"

Is there any command or easy method for accomplish it or should I write some switch for it?

score 12 · Answer 1 · answered Mar 07 '12 at 17:03

12

echo "ibase=16; obase=2; 5F" | bc

answered Mar 07 '12 at 17:03

Alex Howansky

Thanks, it is the same as my selected correct answer, I've chosen it since there is explanation – srnka Mar 12 '12 at 15:53
4

This is not the same as the selected answer. This has `5F`, whereas the selected answer has `5f`. This answer works in `bc` 1.06.95, wheras the selected answer does not. – nrz Apr 24 '17 at 16:28

score 10 · Accepted Answer · answered Mar 07 '12 at 17:12

10

I used 'bc' command in Linux. (much more complex calculator than converting!)

echo 'ibase=16;obase=2;5f' | bc

ibase parameter is the input base (hexa in this case), and obase the output base (binary).

Hope it helps.

answered Mar 07 '12 at 17:12

Luchux

2

Set `obase` before `ibase`. If `ibase` is defined first, `bc` will try to interpret `obase` as if it is written in `ibase`, with possibly erroneous results. See [this question](http://stackoverflow.com/questions/9889839/bc-and-its-ibase-obase-options). – mcmlxxxvi Feb 06 '14 at 10:11
4

Using`bc` version 1.06.95 `echo 'ibase=16;obase=2;5f' | bc` produces error: `(standard_in) 1: syntax error`. However, `echo 'ibase=16;obase=2;5F' | bc` works and produces `1011111`. – nrz Apr 24 '17 at 16:25

kev · Answer 3 · 2012-03-09T14:56:36.753

8

$ printf '\x5F' | xxd -b | cut -d' ' -f2
01011111

Or

$ dc -e '16i2o5Fp'
1011111

The i command will pop the top of the stack and use it for the input base.
Hex digits must be in upper case to avoid collisions with dc commands and are not limited to A-F if the input radix is larger than 16.
The o command does the same for the output base.
The p command will print the top of the stack with a newline after it.

edited Mar 09 '12 at 14:56

answered Mar 07 '12 at 17:04

kev

Thanks for response, it's great to have so many ways of achieving this task :) I've chosen the "bc" variant – srnka Mar 12 '12 at 15:53

score 2 · Answer 4 · answered Mar 09 '12 at 15:02

2

Perl’s printf already knows binary:

$ perl -e 'printf "%08b\n", 0x5D'
01011101

answered Mar 09 '12 at 15:02

tchrist

score 1 · Answer 5 · answered Nov 12 '17 at 19:47

Here's an example:

echo -n 5f5f5f5f5f | cryptocli dd -decoders hex -encoders binary_string

Yields:

0101111101011111010111110101111101011111

The opposite also works.

NB: It's not perfect and much work needs to be done but it is working.

5 Answers5