webfinger

#!/bin/bash
# webfinger (macOS)
# needs GNU getopt since macOS doesn't support relevant options
# and jq - use `brew install gnu-getopt jq`

if [ ! `which jq` ]
then
    echo Installing 'jq'
    brew install jq
fi

set -euo pipefail

rel=
verbose=

rawurlencode() {
    local string="${1}"
    local strlen=${#string}
    local encoded=""
    local pos c o

    for (( pos=0 ; pos<strlen ; pos++ )); do
        c=${string:$pos:1}
        case "$c" in
            [-_.~a-zA-Z0-9] ) o="${c}" ;;
            * )               printf -v o '%%%02x' "'$c"
        esac
        encoded+="${o}"
    done
    echo "${encoded}"    # You can either set a return variable (FASTER)
    REPLY="${encoded}"   #+or echo the result (EASIER)... or both... :p
}

usage() {
>&2 cat << EOF
Usage: $0
    [ -v | --verbose ]
    [ -r | --rel | --REL input ]
    <user@domain>
EOF
exit 1
}

args=$(/opt/homebrew/opt/gnu-getopt/bin/getopt -a -o hvr: --long help,verbose,rel:,REL: -- "$@")
if [[ $? -gt 0 ]]; then
  usage
fi

eval set -- ${args}
while :
do
  case $1 in
    -h | --help) usage; shift;;
    -v | --verbose) verbose=true; shift;;
    -r | --rel | --REL) rel=$2; shift 2;;
    # -- means the end of the arguments; drop this, and break out of the while loop
    --) shift; break ;;
    *) >&2 echo Unsupported option: $1
       usage ;;
  esac
done

if [[ $# -eq 0 ]]; then
  usage
fi

name=`echo $1 | sed 's/\(.*\)@\(.*\)$/\1/'`
domain=`echo $1 | sed 's/\(.*\)@\(.*\)$/\2/'`
server=$domain

address=${name}@${domain}
resource=acct:$(rawurlencode $address)

if [ ! -n "${rel}" ]; then
    command="curl -s -H \"Accept: application/jrd+json\" https://${server}/.well-known/webfinger?resource=${resource}"
else
    command="curl -s -H \"Accept: application/jrd+json\" https://${server}/.well-known/webfinger?resource=${resource}&rel=${rel}"
fi

if [ -n "${verbose}" ]
then
    echo ${command}
    echo
fi

result=`${command}`

echo $result | jq .