Quick fix: string to hex conversion in bash

Just the other day a had to do some simple string to hex conversion without having any other tool available. Thanks to bash’s arithmetic features, it’s easy to implement; just the lack of a strindex() function made it harder than it needs to be, but over there at stackoverflow I found inspirations.

Usage:

$ s2h foobar
666F6F626172
$ h2s 666F6F626172
foobar

Check against working tool:

$ echo -n "foobar" | hd
00000000  66 6f 6f 62 61 72                                 |foobar|
00000006

Full code:

trindex() {
    X="${1%%$2*}"
    [[ "$X" = "$1" ]] && echo -1 || echo "$[ ${#X} ]"
}

function s2h () {
    a=$1
    out=""
    for ((i=0;i<${#a};i++)); do
        tmp=$(printf %02X \'${a:$i:1})
        out=${out}${tmp}
    done
    echo $out
}

# echo -e "\x48"

function h2s () {
    a=$1
    out=""
    for ((i=0;i<${#a};i=i++)); do
        tchar="\x${a:$i:2}"
        out=${out}$(echo -ne $tchar)
        i=$((i+2))
    done
    echo $out
}