Converting decimal to hexadecimal in bash script

Question

I want to convert a decimal number (loop index number) in a bash script to hexadecimal to be used by another command. Something like:

for ((i=1; i<=100; i++))
do

     a=convert-to-decimal($i)
     echo "$a"

done

Where a should be hexadecimal with four digits and hex identifier. For example if value of i is 100, the value of a should be 0x0064. How to do it?

Possible duplicate of [Convert decimal to hexadecimal in UNIX shell script](http://stackoverflow.com/questions/378829/convert-decimal-to-hexadecimal-in-unix-shell-script) — TayTay, Feb 10 '16 at 16:03

score 4 · Accepted Answer · edited Feb 10 '16 at 16:15

4

You can use printf.

$ printf "0x%04x" 100
0x0064

In your example you'd probably use a="$(printf '0x%04x' $i)".

edited Feb 10 '16 at 16:15

gniourf_gniourf

44,650
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answered Feb 10 '16 at 16:05

Wander Nauta

18,832
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2

Or `printf -v a '0x%04x' $i` instead of process substitution. – Benjamin W. Feb 10 '16 at 16:07
@BenjaminW. You certainly mean _command substitution._ But your point is correct. – gniourf_gniourf Feb 10 '16 at 16:13
@gniourf_gniourf I absolutely do! – Benjamin W. Feb 10 '16 at 16:14
1

Actually 0x can be left off. `#` flag adds this automatically. So `printf "%#06x" 100` gives `0x0064`. The only question remains if the OP needs lower case of upper case hex digits. In the later case the `X` specifier should be used. – TrueY Feb 10 '16 at 16:15
@TrueY: feel free to edit the answer to improve it! (or write your own answer). – gniourf_gniourf Feb 10 '16 at 16:17

Alex Nikas · Answer 2 · 2016-02-10T16:28:58.247

1

That's what you're looking for

for i in seq 1 100; do printf '%x\n' $i done

edited Feb 10 '16 at 16:28

answered Feb 10 '16 at 16:21

Alex Nikas

83
8

Converting decimal to hexadecimal in bash script

2 Answers2