Name

Create Per-Directory Config Structure

Synopsis

void *module_create_dir_config(pool *pPool,char *szDir)

This structure is called once per module, with szDir set to NULL, when the main host’s configuration is initialized and again for each <Directory>, <Location>, or <File> section in the Config files containing a directive from this module, with szPath set to the directory. Any per-directory directives found outside <Directory>, <Location>, or <File> sections end up in the NULL configuration. It is also called when .htaccess files are parsed, with the name of the directory in which they reside. Because this function is used for .htaccess files, it may also be called after the initializer is called. Also, the core caches per-directory configurations arising from .htaccess files for the duration of a request, so this function is called only once per directory with an .htaccess file.

If a module does not support per-directory configuration, any directives that appear in a <Directory> section override the per-server configuration unless precautions are taken. The usual way to avoid this is to set the req _overrides member appropriately in the command table — see later in this section.

The purpose of this function is to allocate and initialize the memory required for any per-directory configuration. It returns a pointer to the allocated memory. See Example 21-2 (1.3) for an excerpt from mod_rewrite.c.

Example

Example 21-2. mod_rewrite.c

static void *config_perdir_create(pool *p, char *path)
{
    rewrite_perdir_conf *a;

    a = (rewrite_perdir_conf *)ap_pcalloc(p, sizeof(rewrite_perdir_conf));

    a->state           = ENGINE_DISABLED;
    a->options         = OPTION_NONE;
    a->baseurl         = NULL;
    a->rewriteconds    = ap_make_array(p, 2, sizeof(rewritecond_entry));
    a->rewriterules    = ap_make_array(p, 2, sizeof(rewriterule_entry));

    if (path == NULL) {
        a->directory = NULL;
    }
    else {
        /* make sure it has a trailing slash */
        if (path[strlen(path)-1] == '/') {
            a->directory = ap_pstrdup(p, path);
        }
        else {
            a->directory = ap_pstrcat(p, path, "/", NULL);
        }
    }

    return (void *)a;
}

This function allocates memory for a rewrite_ perdir_conf structure (defined elsewhere in mod_rewrite.c) and initializes it. Since this function is called for every <Directory> section, regardless of whether it contains any rewriting directives, the initialization makes sure the engine is disabled unless specifically enabled later.

The only changes for 2.0 in this are that pool becomes apr_pool_t and ap_pcalloc( ) becomes apr_pcalloc().