Convert decimal to hex in Bash?

A quicky for my archives: convert decimal to hex in Bash, and convert hexadecimal to decimal, in Bash. In mathematics and computing, hexadecimal (also base 16, or hex) is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0-9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a-f) to represent values ten to fifteen. If you want to convert hexadecimal values to decimal and decimal values to hexadecimal, here’s how. All on the bash prompt…

You can use your Linux Bash shell to easily convert decimal values to hexadecimal, and vice versa. For example:

Decimal to hexadecimal in bash

Convert decimal to hexadecimal in Bash:

printf '%x\n' 26560
67c0

Hexadecimal to decimal

Convert hexadecimal to decimal in Bash:

echo $((0x000067c0))
26560

echo $((0x67c0))
26560

printf '%d\n' 0x67c0
26560

Bash function to generate a random alphanumeric string

Convert Unix timestamps to dates in Bash

How to convert Unix timestamps to dates in Bash is a little irrelevant in a post on converting decimal to hex in Bash, but it’s still converting something in Bash :-) .

Suppose you have an Unix timestamp that you want to convert to a date, here is how with two one liners:

date -d @timestamp

date -d @($date -u +timestamp)

And vice versa, convert a date to an Unix timestamp:

date -d '04/05/2017 11:13:00' +"%s"

The date string is too complex to be documented in the man page, so it is described in info: info '(coreutils) date invocation'.