Convert decimal to hexadecimal in UNIX shell script

Question

Tried printf(1)?

printf "%x\n" 34
22

There are probably ways of doing that with builtin functions in all shells but it would be less portable. I've not checked the POSIX sh specs to see whether it has such capabilities.

echo "obase=16; 34" | bc

If you want to filter a whole file of integers, one per line:

( echo "obase=16" ; cat file_of_integers ) | bc

Hexidecimal to decimal:

$ echo $((0xfee10000))
4276158464

Decimal to hexadecimal:

$ printf '%x\n' 26
1a

bash-4.2$ printf '%x\n' 4294967295
ffffffff

bash-4.2$ printf -v hex '%x' 4294967295
bash-4.2$ echo $hex
ffffffff

Sorry my fault, try this...

#!/bin/bash
:

declare -r HEX_DIGITS="0123456789ABCDEF"

dec_value=$1
hex_value=""

until [ $dec_value == 0 ]; do

    rem_value=$((dec_value % 16))
    dec_value=$((dec_value / 16))

    hex_digit=${HEX_DIGITS:$rem_value:1}

    hex_value="${hex_digit}${hex_value}"

done

echo -e "${hex_value}"

Example:

$ ./dtoh 1024
400

Try:

printf "%X\n" ${MY_NUMBER}

In my case, I stumbled upon one issue with using printf solution:

$ printf "%x" 008 bash: printf: 008: invalid octal number

The easiest way was to use solution with bc, suggested in post higher:

$ bc <<< "obase=16; 008" 8