trace/control.c

   1 /*
   2  * Interface for configuring and controlling the state of tracing events.
   3  *
   4  * Copyright (C) 2011 Lluís Vilanova <vilanova@ac.upc.edu>
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2.  See
   7  * the COPYING file in the top-level directory.
   8  */
   9
  10 #include "trace/control.h"
  11
  12
  13 void trace_backend_init_events(const char *fname)
  14 {
  15     if (fname == NULL) {
  16         return;
  17     }
  18
  19     FILE *fp = fopen(fname, "r");
  20     if (!fp) {
  21         fprintf(stderr, "error: could not open trace events file '%s': %s\n",
  22                 fname, strerror(errno));
  23         exit(1);
  24     }
  25     char line_buf[1024];
  26     while (fgets(line_buf, sizeof(line_buf), fp)) {
  27         size_t len = strlen(line_buf);
  28         if (len > 1) {              /* skip empty lines */
  29             line_buf[len - 1] = '\0';
  30             if ('#' == line_buf[0]) { /* skip commented lines */
  31                 continue;
  32             }
  33             if (!trace_event_set_state(line_buf, true)) {
  34                 fprintf(stderr,
  35                         "error: trace event '%s' does not exist\n", line_buf);
  36                 exit(1);
  37             }
  38         }
  39     }
  40     if (fclose(fp) != 0) {
  41         fprintf(stderr, "error: closing file '%s': %s\n",
  42                 fname, strerror(errno));
  43         exit(1);
  44     }
  45 }