text: 
  /*
   * Copyright (C) Igor Sysoev
   * Copyright (C) Nginx, Inc.
   */
  
  
  #include <ngx_config.h>
  #include <ngx_core.h>
  #include <ngx_http.h>
  
  
  static ngx_int_t ngx_http_stub_status_variable(ngx_http_request_t *r,
      ngx_http_variable_value_t *v, uintptr_t data);
  static ngx_int_t ngx_http_stub_status_add_variables(ngx_conf_t *cf);
  
  static char *ngx_http_set_status(ngx_conf_t *cf, ngx_command_t *cmd,
                                   void *conf);
  
  static ngx_command_t  ngx_http_status_commands[] = {
  
      { ngx_string("stub_status"),
        NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_http_set_status,
        0,
        0,
        NULL },
  
        ngx_null_command
  };
  
  
  
  static ngx_http_module_t  ngx_http_stub_status_module_ctx = {
      ngx_http_stub_status_add_variables,    /* preconfiguration */
      NULL,                                  /* postconfiguration */
  
      NULL,                                  /* create main configuration */
      NULL,                                  /* init main configuration */
  
      NULL,                                  /* create server configuration */
      NULL,                                  /* merge server configuration */
  
      NULL,                                  /* create location configuration */
      NULL                                   /* merge location configuration */
  };
  
  
  ngx_module_t  ngx_http_stub_status_module = {
      NGX_MODULE_V1,
      &ngx_http_stub_status_module_ctx,      /* module context */
      ngx_http_status_commands,              /* module directives */
      NGX_HTTP_MODULE,                       /* module type */
      NULL,                                  /* init master */
      NULL,                                  /* init module */
      NULL,                                  /* init process */
      NULL,                                  /* init thread */
      NULL,                                  /* exit thread */
      NULL,                                  /* exit process */
      NULL,                                  /* exit master */
      NGX_MODULE_V1_PADDING
  };
  
  
  static ngx_http_variable_t  ngx_http_stub_status_vars[] = {
  
      { ngx_string("connections_active"), NULL, ngx_http_stub_status_variable,
        0, NGX_HTTP_VAR_NOCACHEABLE, 0 },
  
      { ngx_string("connections_reading"), NULL, ngx_http_stub_status_variable,
        1, NGX_HTTP_VAR_NOCACHEABLE, 0 },
  
      { ngx_string("connections_writing"), NULL, ngx_http_stub_status_variable,
        2, NGX_HTTP_VAR_NOCACHEABLE, 0 },
  
      { ngx_string("connections_waiting"), NULL, ngx_http_stub_status_variable,
        3, NGX_HTTP_VAR_NOCACHEABLE, 0 },
  
      { ngx_null_string, NULL, NULL, 0, 0, 0 }
  };
  
  
  static ngx_int_t ngx_http_status_handler(ngx_http_request_t *r)
  {
      size_t             size;
      ngx_int_t          rc;
      ngx_buf_t         *b;
      ngx_chain_t        out;
      ngx_atomic_int_t   ap, hn, ac, rq, rd, wr, wa;
  
      if (r->method != NGX_HTTP_GET && r->method != NGX_HTTP_HEAD) {
          return NGX_HTTP_NOT_ALLOWED;
      }
  
      rc = ngx_http_discard_request_body(r);
  
      if (rc != NGX_OK) {
          return rc;
      }
  
      r->headers_out.content_type_len = sizeof("text/plain") - 1;
      ngx_str_set(&r->headers_out.content_type, "text/plain");
      r->headers_out.content_type_lowcase = NULL;
  
      if (r->method == NGX_HTTP_HEAD) {
          r->headers_out.status = NGX_HTTP_OK;
  
          rc = ngx_http_send_header(r);
  
          if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
              return rc;
          }
      }
  
      size = sizeof("Active connections:  \n") + NGX_ATOMIC_T_LEN
             + sizeof("server accepts handled requests\n") - 1
             + 6 + 3 * NGX_ATOMIC_T_LEN
             + sizeof("Reading:  Writing:  Waiting:  \n") + 3 * NGX_ATOMIC_T_LEN;
  
      b = ngx_create_temp_buf(r->pool, size);
      if (b == NULL) {
          return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }
  
      out.buf = b;
      out.next = NULL;
  
      ap = *ngx_stat_accepted;
      hn = *ngx_stat_handled;
      ac = *ngx_stat_active;
      rq = *ngx_stat_requests;
      rd = *ngx_stat_reading;
      wr = *ngx_stat_writing;
      wa = *ngx_stat_waiting;
  
      b->last = ngx_sprintf(b->last, "Active connections: %uA \n", ac);
  
      b->last = ngx_cpymem(b->last, "server accepts handled requests\n",
                           sizeof("server accepts handled requests\n") - 1);
  
      b->last = ngx_sprintf(b->last, " %uA %uA %uA \n", ap, hn, rq);
  
      b->last = ngx_sprintf(b->last, "Reading: %uA Writing: %uA Waiting: %uA \n",
                            rd, wr, wa);
  
      r->headers_out.status = NGX_HTTP_OK;
      r->headers_out.content_length_n = b->last - b->pos;
  
      b->last_buf = (r == r->main) ? 1 : 0;
      b->last_in_chain = 1;
  
      rc = ngx_http_send_header(r);
  
      if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
          return rc;
      }
  
      return ngx_http_output_filter(r, &out);
  }
  
  
  static ngx_int_t
  ngx_http_stub_status_variable(ngx_http_request_t *r,
      ngx_http_variable_value_t *v, uintptr_t data)
  {
      u_char            *p;
      ngx_atomic_int_t   value;
  
      p = ngx_pnalloc(r->pool, NGX_ATOMIC_T_LEN);
      if (p == NULL) {
          return NGX_ERROR;
      }
  
      switch (data) {
      case 0:
          value = *ngx_stat_active;
          break;
  
      case 1:
          value = *ngx_stat_reading;
          break;
  
      case 2:
          value = *ngx_stat_writing;
          break;
  
      case 3:
          value = *ngx_stat_waiting;
          break;
  
      /* suppress warning */
      default:
          value = 0;
          break;
      }
  
      v->len = ngx_sprintf(p, "%uA", value) - p;
      v->valid = 1;
      v->no_cacheable = 0;
      v->not_found = 0;
      v->data = p;
  
      return NGX_OK;
  }
  
  
  static ngx_int_t
  ngx_http_stub_status_add_variables(ngx_conf_t *cf)
  {
      ngx_http_variable_t  *var, *v;
  
      for (v = ngx_http_stub_status_vars; v->name.len; v++) {
          var = ngx_http_add_variable(cf, &v->name, v->flags);
          if (var == NULL) {
              return NGX_ERROR;
          }
  
          var->get_handler = v->get_handler;
          var->data = v->data;
      }
  
      return NGX_OK;
  }
  
  
  static char *ngx_http_set_status(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_status_handler;
  
      return NGX_CONF_OK;
  }
  