[SOLVED] filter unique parameters from file

Issue

i have file contains urls plus params like following

https://example.com/endpoint/?param1=123&param2=1212
https://example.com/endpoint/?param3=123&param1=98989
https://example.com/endpoint/endpoint3/?param2=123
https://example.com/endpoint/endpoint2/?param1=123
https://example.com/endpoint/endpoint2/
https://example.com/endpoint/endpoint5/"//i.example.com/00/s/Nzk5WDEwMjQ=/z/47IAAOSwBu5hXIKF

and i need to filter only urls with unique params the desired output

http://example.com/endpoint/?param1=123&param2=1212
https://example.com/endpoint/?param3=123&param1=98989
https://example.com/endpoint/endpoint3/?param2=123

i managed to filter only urls with params with grep grep -E '(\?[a-zA-Z0-9]{1,9}\=)'

but i need to filter params in the same time so i tried with awk with the same regex but it gives error

awk '{sub(\?[a-zA-Z0-9]{1,9}\=)} !seen[$0]++'

update

i am sorry for editing the desired output but when i tried the scripts i figured out that their a lot of carbege in my file need to filter too. i tried @James Brown with some editing and it looks good till the end line it dose not filter it unfortunately

awk -F '?|&' '$2&&!a[$2]++'

and to be more clear why the that output is good for me it chosed the 1 st line because it has at least param1 2nd line because it has at least param3 3 line because it has at least param2 the comparison method here is choose just unique parameter whatever it concatenate with others with & char or not

Solution

Edited version after the reqs changes some:

$ awk -F? '{                   # ? as field delimiter
    split($2,b,/&/)            # split at & to get whats between ? and &
    if(b[1]!=""&&!a[b[1]]++)   # no ? means no $2
        print
}' file

Output as expected. Original answer was:

A short one:

$ awk -F? '$2&&!a[$2]++' file

Explained: Split records at ? (-F?) and if there is a second field ($2) and (&&) it is unique this far by counting the instances of the parameters in the array a (!a[$2]++), output it.

Answered By - James Brown