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 (!trace_event_set_state(line_buf, true)) {
  31                 fprintf(stderr,
  32                         "error: trace event '%s' does not exist\n", line_buf);
  33                 exit(1);
  34             }
  35         }
  36     }
  37     if (fclose(fp) != 0) {
  38         fprintf(stderr, "error: closing file '%s': %s\n",
  39                 fname, strerror(errno));
  40         exit(1);
  41     }
  42 }