Shell Script – Binary to Hexadecimal and Decimal Conversion

arithmeticbinaryshell-script

I have a context where I need to convert binary to hexadecimal and decimal and viceversa in a shell script. Can someone suggest me a tool for this?

Best Answer

It's fairly straightforward to do the conversion from binary in pure bash (echo and printf are builtins):

Binary to decimal

$ echo "$((2#101010101))"
341

Binary to hexadecimal

$ printf '%x\n' "$((2#101010101))"
155

Going back to binary using bash alone is somewhat more complex, so I suggest you see the other answers for solutions to that.

Related Solutions

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

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

...

Bash – ASCII to Binary and Binary to ASCII conversion tools

$ echo AB | perl -lpe '$_=unpack"B*"'
0100000101000010
$ echo 0100000101000010 | perl -lpe '$_=pack"B*",$_'
AB

-e expression evaluate the given expression as perl code
-p: sed mode. The expression is evaluated for each line of input, with the content of the line stored in the $_ variable and printed after the evaluation of the expression.
-l: even more like sed: instead of the full line, only the content of the line (that is, without the line delimiter) is in $_ (and a newline is added back on output). So perl -lpe code works like sed code except that it's perl code as opposed to sed code.
unpack "B*" works on the $_ variable by default and extracts its content as a bit string walking from the highest bit of the first byte to the lowest bit of the last byte.
pack does the reverse of unpack. See perldoc -f pack for details.

With spaces:

$ echo AB | perl -lpe '$_=join " ", unpack"(B8)*"'
01000001 01000010
$ echo 01000001 01000010 | perl -lape '$_=pack"(B8)*",@F'
AB

(it assumes the input is in blocks of 8 bits (0-padded)).

With unpack "(B8)*", we extract 8 bits at a time, and we join the resulting strings with spaces with join " ".