Test,Nginx Hello World Module

 ngx_addon_name=ngx_http_mytest_module
 HTTP_MODULES="$HTTP_MODULES ngx_http_mytest_module"
 NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_mytest_module.c"

ngx_http_mytest_module.c

 #include <ngx_core.h>
 #include <ngx_http.h>
 #include <nginx.h>

 static char *ngx_http_mytest(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
 static ngx_int_t ngx_http_mytest_handler(ngx_http_request_t *r);

 static ngx_command_t ngx_http_mytest_commands[] = {
     {ngx_string("mytest"),
         NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_HTTP_LMT_CONF | NGX_CONF_NOARGS,
         ngx_http_mytest,
         NGX_HTTP_LOC_CONF_OFFSET,
         ,
         NULL},

     ngx_null_command
 };

 static ngx_http_module_t ngx_http_mytest_module_ctx = {
 NULL,
 NULL,
 NULL,
 NULL,
 NULL,
 NULL,
 NULL,
 NULL
 };

 ngx_module_t ngx_http_mytest_module = {
 NGX_MODULE_V1,
 &ngx_http_mytest_module_ctx,
 ngx_http_mytest_commands,
 NGX_HTTP_MODULE,
 NULL,
 NULL,
 NULL,
 NULL,
 NULL,
 NULL,
 NULL,
 NGX_MODULE_V1_PADDING
 };

 static char *ngx_http_mytest(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
     ngx_http_core_loc_conf_t *clcf;
     clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
     clcf->handler = ngx_http_mytest_handler;

     return NGX_CONF_OK;
 }

 static ngx_int_t ngx_http_mytest_handler(ngx_http_request_t *r)
 {
     if(!(r->method & NGX_HTTP_GET))
         return NGX_HTTP_NOT_ALLOWED;

     ngx_int_t rc = ngx_http_discard_request_body(r);
     if(rc != NGX_OK)
         return rc;

     ngx_str_t type = ngx_string("text/plain");
     ngx_str_t response = ngx_string("Hello World!");
     r->headers_out.status = NGX_HTTP_OK;
     r->headers_out.content_length_n = response.len;
     r->headers_out.content_type = type;

     rc = ngx_http_send_header(r);
     if(rc == NGX_ERROR || rc > NGX_OK || r->header_only)
         return rc;

     ngx_buf_t *b;
     b = ngx_create_temp_buf(r->pool, response.len);
     if(b == NULL)
         return NGX_HTTP_INTERNAL_SERVER_ERROR;

     ngx_memcpy(b->pos, response.data, response.len);
     b->last = b->pos + response.len;
     b->last_buf = ;

     ngx_chain_t out;
     out.buf = b;
     out.next = NULL;

     return ngx_http_output_filter(r, &out);
 }

./configure --add-module=