Hi,
I wrote a week or so ago about detecting updates.
You mentioned that the best way is to make a new 
callback and said you'd put it on your todo list.
I'm sure this todo list of yours is getting REALLY 
long, so I tried to find where I could put such a call 
back inside htsback.c and/or htscore.c. There are 
other callbacks I could use as well, so I thought I 
might try to understand the code a bit more. It is a 
bit hard though, some functions are very long and hard 
for me to follow and unfornately I don't know how to 
read French (except menus :) So, after many hours I 
made no real progress.

Anyway, I began to realise that a lot of info is 
already in the log messages. There are 233 of these 
and I thought it might be useful to have a single 
callback for these rather than making any new 
callbacks. Then an API user could parse these messages 
for information and hints (This would actually solve 
my 'update hint' problem, for example.) It would also 
allow an API user to integrate your messages with 
other messages, which could be very handy.

So far (as of version 3.08-3), you write to the logs 
VERY consistently, so it would be easy to convert the 
fprintf calls (and the fspc calls) to a couple of 
functions which formats the string (using vprintf) and 
then passes it to a callback before writing to the 
log. I could write the functions and send them to you 
if you don't have time, then, if you are willing, you 
could do a simple search/replace and change your 
fprintf calls that write to the log to the new ones. I 
have checked your code very closely and you could 
easily do this by replacing these three strings:
    fprintf(opt
    fprintf(httrack
    fprintf(cache

Please let me know if this sounds acceptable to you 
and I will send you the code (directly via e-mail, 
because this form mangles lines) or I could apply the 
changes directly to the next release if you would 
prefer.

many thanks,
john