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     int ret;
  16
  17     if (fname == NULL) {
  18         return;
  19     }
  20
  21     FILE *fp = fopen(fname, "r");
  22     if (!fp) {
  23         fprintf(stderr, "error: could not open trace events file '%s': %s\n",
  24                 fname, strerror(errno));
  25         exit(1);
  26     }
  27     char line_buf[1024];
  28     while (fgets(line_buf, sizeof(line_buf), fp)) {
  29         size_t len = strlen(line_buf);
  30         if (len > 1) {              /* skip empty lines */
  31             line_buf[len - 1] = '\0';
  32             if ('#' == line_buf[0]) { /* skip commented lines */
  33                 continue;
  34             }
  35             if ('-' == line_buf[0]) {
  36                 ret = trace_event_set_state(line_buf+1, false);
  37             } else {
  38                 ret = trace_event_set_state(line_buf, true);
  39             }
  40             if (!ret) {
  41                 fprintf(stderr,
  42                         "error: trace event '%s' does not exist\n", line_buf);
  43                 exit(1);
  44             }
  45         }
  46     }
  47     if (fclose(fp) != 0) {
  48         fprintf(stderr, "error: closing file '%s': %s\n",
  49                 fname, strerror(errno));
  50         exit(1);
  51     }
  52 }