urldecode
urldecode OPTIONS [URL_ENCODED_STRING]
urldecode is a simple command line utility to URL decode content. By default it reads from standard input and writes to standard out. You can also specifty the string to decode as a command line parameter.
You can provide the URL encoded string as a command line parameter or if none present it will be read from standard input.
echo ‘This%20is%20the%20string%20to%20encode%20&%20nothing%20else%0A’ | urldecode
would yield (without the double quotes)
"This is the string to encode & nothing else!"