Question

I’m trying to programmatically map gitweb-format query strings to cgit query strings to transition fully to cgit without breaking old gitweb-based urls pointing to my repositories which are scattered here and there around the web. I’ve seen some regex-based URL rewriting rules such as the following:

http://www.clearchain.com/blog/posts/cgit-upgrade-gitweb-retired

but I’m trying to actually understand the variables in the query string to make sure I get it right, and I’ll be using a tiny CGI program rather than mod_rewrite or whatever do to the remapping. In particular, I don’t understand the semantics of the h, hb, and hp hashes and how they map to cgit’s id query variables for different types of queries.

Can anyone familiar with them fill me in or point me to a good resource?

Answer 1

Basically

• id comes from hashb if the gitweb url uses hashb, otherwise from hash.
• id2 comes from hashpbif the gitweb url useshashpb, otherwise fromhashp`.
• the rest is pretty straightforward.

Here’s the script I’m using now (no external commands invoked if your shell doesn’t suck):

#!/bin/sh

q=$QUERY_STRING
repo=
action=
hash=
hashp=
file=

while test "$q" ; do
x=${q%%;*}
case "$x" in
p=*) repo=${x#p=} ;;
a=*commit*) action=commit ;;
a=*plain*) action=plain ;;
a=*summary*) action= ;;
a=*log*) action=log ;;
a=*) action=${x#a=} ;;
h=*) hash=${x#h=} ;;
hb=*) hashb=${x#hb=} ;;
hp=*) hashp=${x#hp=} ;;
hpb=*) hashpb=${x#hpb=} ;;
f=*) file=${x#f=} ;;
esac
t=${q#*;}
test "$t" = "$q" && break
q=$t
done

test "$hashb" && hash=$hashb
test "$hashpb" && hashp=$hashpb

loc=/cgit

if test "$repo" ; then
        loc=$loc/$repo
        if test "$action" ; then
                loc=$loc/$action
                if test "$file" ; then
                        loc=$loc/$file
                fi
        fi
        if test "$hash" ; then
                loc=$loc/\?id=$hash 
                if test "$hashp" ; then
                        loc=$loc\&id2=$hashp
                fi
        fi
fi

printf 'Status: 301 Moved Permanently\nLocation: %s\n\n' "$loc"