Apache module - How to check existence of directive in httpd.conf -

i trying write sample apache module read config file file path specified in httpd.conf that:

<location ~ /(?!.*\.(png|jpeg|jpg|gif|bmp|tif)$)>         setinputfilter sample_input_filter         setoutputfilter sample_output_filter         configfilepath "/etc/httpd/conf.d/sample/sample.config" </location> 

at command record structure, do:

static const command_rec config_check_cmds[] = {     ap_init_take1( "configfilepath", read_config_file, null, or_all, "sample config"),     { null } }; 

i set:

module ap_module_declare_data sample_module = {     standard20_module_stuff,      create_dir_config,          /* create per-dir   config structures */     null,                   /* merge per-dir    config structures */     null,                   /* create per-server config structures */     null,                   /* merge per-server config structures */     config_check_cmds,              /* table of config file commands */     sample_register_hooks   /* register hooks */ }; 

i read config file path successfully. , want check if "configfilepath" not specified in httpd.conf, show error @ console when use "service httpd restart"

how that?

you'd register ap_hook_post_config hook , verification of required settings there. aware that hook called twice documented in answer here: init modules in apache2

see example post config hook implementation here: http://svn.apache.org/repos/asf/httpd/httpd/tags/2.3.0/modules/examples/mod_example_hooks.c