Bash oauth with curl on OSX

curl_oauth.sh

#!/usr/bin/env bash

# parameters
url="https://example.com"
client_id="foo"
client_secret="bar"

# request access token
oauth_path="/oauth2/access_token"
access_token=$(curl -s -H "Accept: application/json" -H "Content-Type: application/x-www-form-urlencoded; charset=utf-8" -H "Authorization: Basic $(echo "$client_id:$client_secret" | tr -d "\n" | base64)" -X POST -d "grant_type=client_credentials" "$url$oauth_path" | sed -e 's/^.*"access_token":"\([^"]*\)".*$/\1/')

# call service using access token
service_path="/foo"
body="{}"
curl -s -H "Content-Type: application/json; charset=utf-8" -H "Authorization: Bearer $access_token" -X POST -d $body "$url$service_path"