Function apply_rewrite_rule

modules/mappers/mod_rewrite.c:4354–4630

* Apply a single RewriteRule */

 * Apply a single RewriteRule
 */
static rule_return_type apply_rewrite_rule(rewriterule_entry *p,
                                           rewrite_ctx *ctx)
{
    ap_regmatch_t regmatch[AP_MAX_REG_MATCH];
    apr_array_header_t *rewriteconds;
    rewritecond_entry *conds;
    int i, rc;
    char *newuri = NULL;
    request_rec *r = ctx->r;
    int is_proxyreq = 0;
    int prefix_added = 0;

    ctx->uri = r->filename;

    if (ctx->perdir) {
        apr_size_t dirlen = strlen(ctx->perdir);

        /*
         * Proxy request?
         */
        is_proxyreq = (   r->proxyreq && r->filename
                       && !strncmp(r->filename, "proxy:", 6));

        /* Since we want to match against the (so called) full URL, we have
         * to re-add the PATH_INFO postfix
         */
        if (r->path_info && *r->path_info) {
            rewritelog(r, 3, ctx->perdir, "add path info postfix: %s -> %s%s",
                       ctx->uri, ctx->uri, r->path_info);
            ctx->uri = apr_pstrcat(r->pool, ctx->uri, r->path_info, NULL);
        }

        /* Additionally we strip the physical path from the url to match
         * it independent from the underlying filesystem.
         */
        if (!is_proxyreq && strlen(ctx->uri) >= dirlen &&
            !strncmp(ctx->uri, ctx->perdir, dirlen)) {

            rewritelog(r, 3, ctx->perdir, "strip per-dir prefix: %s -> %s",
                       ctx->uri, ctx->uri + dirlen);
            ctx->uri = ctx->uri + dirlen;
        }
    }

    /* Try to match the URI against the RewriteRule pattern
     * and exit immediately if it didn't apply.
     */
    rewritelog(r, 3, ctx->perdir, "applying pattern '%s' to uri '%s'",
                p->pattern, ctx->uri);

    rc = !ap_regexec(p->regexp, ctx->uri, AP_MAX_REG_MATCH, regmatch, 0);
    if (! (( rc && !(p->flags & RULEFLAG_NOTMATCH)) ||
           (!rc &&  (p->flags & RULEFLAG_NOTMATCH))   ) ) {
        return RULE_RC_NOMATCH;
    }

    /* It matched, wow! Now it's time to prepare the context structure for
     * further processing