How to write binary data in Bash

Question

Let us say there is a variable in bash script with value \"001\" how can i write this binary data into a file as bits (as \"001\" not \"1\") echo writes it as string but i w

Answer 1

Just use the %b in the printf:

printf "%b" "\012"
printf "%b" "\x0a"

%b - Print the associated argument while interpreting backslash escapes in there

so, above both prints binary value for the decimal 10.

printf "%b" "\x0a" | od -bc

output

0000000   012                                                            
          \n      

you can even mix

printf "%b" "\12\xa\n" | od -bc

0000000   012 012 012                                                    
          \n  \n  \n