removing first letters in a string using bash under cgi

Question

I'm trying to path a web address to a bash script run under cgi. I search a little and found this link. From what I understood, this line should separate the variable from it's value:

USERNAME=`echo "$QUERY_STRING" | sed -n 's/^.*username=\([^&]*\).*$/\1/p' | sed "s/%20/ /g"

So, reading about sed, I have concluded that this line should be sufficient for my needs:

url='echo "$QUERY_STRING" | sed "s/url=\(.*\)/\1/"'

where the input is

url=www.web.address.com

However, the variable get is the string is:

echo "$QUERY_STRING" | sed "s/url=(.*)/\1/" if I tried to remove the apostrophes I get an empty variable. Note that if I simply to the echo command I the desired effect.

How can I separate the url value?

Answer 1

You can use parameter expansion and you won't need sed.

echo "${QUERY_STRING##*=}"

To set a variable to that value:

url=${QUERY_STRING##*=}