Encoding & Decoding

alias urlencode='python -c "import urllib.parse, sys; print(urllib.parse.quote_plus(sys.argv[1])) if len(sys.argv) > 1 else print(urllib.parse.quote_plus(sys.stdin.readline()[0:-1]))"'
alias urldecode='python -c "import urllib.parse, sys; print(urllib.parse.unquote(sys.argv[1])) if len(sys.argv) > 1 else print(urllib.parse.unquote(sys.stdin.readline()[0:-1]))"'

# percent encode
urlencode $VALUE

# HMAC-SHA1 hashing
echo -n $VALUE | openssl dgst -sha1 -hmac $KEY

# Base64
echo -n $VALUE | base64
echo -n $VALUE | base64 --decode

hashing.sh

#!/bin/bash

function hash_hmac {
  digest="$1"
  key="$2"
  data="$3"
  shift 3
  echo -n "$data" | openssl dgst "-$digest" -hmac "$key" "$@"
}

# digest could be sha1, sha256, md5 etc
hash_hmac "$1" "$2" "$3"