Question

I am testing G-WAN server and I’d like using rewrite rules.

With apache the rule is :

RewriteRule ^(.+)-(.+)-(.+)-1.jpg$ imagesproduitnew/$3/$2.jpg [L]

I am trying to do it by handlers JPG, but I have lot of difficulties.

Has anybody already done something like that ?

---

My handlers is called url_wr.c in the path /0.0.0.0_80/#0.0.0.0/handlers
Here is the script

int init(char *argv[], int argc);

int main(int argc, char *argv[])
{
   const long state = (long)argv[0];
   if(state == HDL_AFTER_READ)
   {
      xbuf_t *read_xbuf = (xbuf_t*)get_env(argv, READ_XBUF);
      xbuf_replfrto(read_xbuf, read_xbuf->ptr, read_xbuf->ptr + 16, "/blog", "/?blog");
   }
   return 255; // execute next connection step
}

int clean(char *argv[], int argc);

In gwan.log, it is not writen loaded url_wr.c
If I put printf in each function, it doesn’t work.
The servlet bloc.c works well.

I also tried tu put the code in handlers/main.c and in the root of gwan directory.

I have only a error.log file for the site which says just error404 without any details of the handlers.

Thanks by advance for your support

Answer 1

You must use a G-WAN connection handler, either to use:

• a plain-rewrite: one example is given at the end of the developers page,

OR,

• a regex library (libc provides regex calls) if you target a more general rewrite scheme. Here is an example in C and the explanations are there, courtesy of “Regular Expressions in C” from the “Linux Gazette”.

This could also be made rom a servlet, but then you would have to trigger a redirection (unless the resource was explicitely placed into a cache). If this is acceptable, then v3.10+ will let you do it in C#, PHP, Python, etc.

---

UPDATE following the code published in the question:

Your init() call is empty so main() is never called. You should do this instead:

// ----------------------------------------------------------------------------
// init() will initialize your data structures, load your files, etc.
// ----------------------------------------------------------------------------
// init() should return -1 if failure (to allocate memory for example)
int init(int argc, char *argv[])
{
   // define which handler states we want to be notified in main():
   // enum HANDLER_ACT { 
   //  HDL_INIT = 0, 
   //  HDL_AFTER_ACCEPT, // just after accept (only client IP address setup)
   //  HDL_AFTER_READ,   // each time a read was done until HTTP request OK
   //  HDL_BEFORE_PARSE, // HTTP verb/URI validated but HTTP headers are not 
   //  HDL_AFTER_PARSE,  // HTTP headers validated, ready to build reply
   //  HDL_BEFORE_WRITE, // after a reply was built, but before it is sent
   //  HDL_HTTP_ERRORS,  // when G-WAN is going to reply with an HTTP error
   //  HDL_CLEANUP };
   //
   u32 *states = (u32*)get_env(argv, US_HANDLER_STATES);
   *states = 1 << HDL_AFTER_READ; // we assume "GET /hello" sent in one shot
   puts("init()");
   return 0;
}

Also, make sure that connection handlers are named main.c. In contrast, content handlers carry the name of the targeted file extension (gif.c, html.c, etc).