A one liner to parse a http query string in bash

parse_query.sh

#
# the following one liner creates a shell variable from every parameter in a
# the query string in the variable QUERY, of the form p1=v1&p2=v2,... and sets it to
# the corresponding value so that parameters can be accessed by its name $p1, $p2, ...
#

for p in ${QUERY//&/ };do kvp=( ${p/=/ } ); k=${kvp[0]};v=${kvp[1]};eval $k=$v;done

If you are just going to assume that nothing is URL encoded and use eval to set variables, then all you really need is:

eval "${QUERY_STRING//&/$'\n'}"