[SOLVED] Convert base64 data into decimal

Issue

CANMIC_BASE64_DATA="FxEYEhkTGhQbFRwWIQcBCAIJAwoECwUMBjEHAQgCCQMKBAsFDAYAgICAgICAgICAgICAAICAgICAgICAgICAgAu003du003d"
CANMIC_HEX_DATA=$(base64 -d -i <<<$CANMIC_BASE64_DATA | hexdump -v -e '/1 "%02x," ')

I get hex data in CANMIC_BASE64_DATA* and then store this data into array

array_len=${#array[@]}

Once I store it into array it store it as decimal. But I was it should be in hex only in array. I need to convert base64 into decimal similar to CANMIC_HEX_DATA dumping.

Solution

Given your base64 encoded string, you can assign each byte to an array.

Either you assign the array with hexadecimal values:

arr1=($(base64 -d <<< "FxEYEhkTGhQbFRwWIQcBCAIJAwoECwUMBjEHAQgCCQMKBAsFDAYAgICAgICAgICAgICAAICAgICAgICAgICAgAu003du003d" | hexdump -v -e '/1 "0x%02x " '))
printf "%s" "${arr1[0]}"
0x17
printf "%d" "${arr1[0]}"
23
printf "%x" "${arr1[0]}"
17

Either you assign your array with decimal values:

arr2=($(base64 -d <<< "FxEYEhkTGhQbFRwWIQcBCAIJAwoECwUMBjEHAQgCCQMKBAsFDAYAgICAgICAgICAgICAAICAgICAgICAgICAgAu003du003d" | hexdump -v -e '/1 "%02d " '))
$ printf "%s" "${arr2[0]}"
23
$ printf "%d" "${arr2[0]}"
23
$ printf "%x" "${arr2[0]}"
17

The only difference is the hexdump format.

Note that you can't deal with binary directly with variable as the shell will refuse to accept it.

For example, with bash, trying var="$(echo -e "\x00")" will result in the error bash: warning: command substitution: ignored null byte in input

Answered By - oliv