khatus_sensor_time.c

   1 #include <assert.h>
   2 #include <ctype.h>
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <signal.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <time.h>
  10 #include <unistd.h>
  11
  12 #include "khatus_lib_log.h"
  13 #include "khatus_lib_sensor.h"
  14 #include "khatus_lib_time.h"
  15
  16 #define usage(...) {print_usage(); fprintf(stderr, "Error:\n    " __VA_ARGS__); exit(EXIT_FAILURE);}
  17
  18 #define MAX_LEN 20
  19 #define END_OF_MESSAGE '\n'
  20
  21 char *argv0 = NULL;
  22
  23 double opt_interval = 1.0;
  24 char *opt_fmt = "%a %b %d %H:%M:%S";
  25 char *fifo_name = NULL;
  26
  27 void
  28 print_usage()
  29 {
  30         printf(
  31             "%s: [OPT ...] FIFO\n"
  32             "\n"
  33             "FIFO = string    # path to fifo file\n"
  34             "OPT = -i int     # interval\n"
  35             "    | -f string  # format string\n"
  36             "    | -h         # help message (i.e. what you're reading now :) )\n",
  37             argv0);
  38 }
  39
  40 void
  41 opt_parse(int argc, char **argv)
  42 {
  43         char c;
  44
  45         while ((c = getopt(argc, argv, "f:i:h")) != -1)
  46                 switch (c) {
  47                 case 'f':
  48                         opt_fmt = calloc(strlen(optarg), sizeof(char));
  49                         strcpy(opt_fmt, optarg);
  50                         break;
  51                 case 'i':
  52                         opt_interval = atof(optarg);
  53                         break;
  54                 case 'h':
  55                         print_usage();
  56                         exit(EXIT_SUCCESS);
  57                 case '?':
  58                         if (optopt == 'f' || optopt == 'i')
  59                                 fprintf(stderr,
  60                                         "Option -%c requires an argument.\n",
  61                                         optopt);
  62                         else if (isprint(optopt))
  63                                 fprintf (stderr,
  64                                         "Unknown option `-%c'.\n",
  65                                         optopt);
  66                         else
  67                                 fprintf(stderr,
  68                                         "Unknown option character `\\x%x'.\n",
  69                                         optopt);
  70                         exit(EXIT_FAILURE);
  71                 default:
  72                         assert(0);
  73                 }
  74         fifo_name = argv[optind];
  75         debug("fifo_name: %s\n", fifo_name);
  76         if (!fifo_name)
  77                 usage("No filename was provided\n");
  78 }
  79
  80 int
  81 get_time(char *buf, char *fmt)
  82 {
  83         time_t t;
  84
  85         t = time(NULL);
  86         strftime(buf, MAX_LEN, fmt, localtime(&t));
  87         return strlen(buf);
  88 }
  89
  90 int
  91 main(int argc, char **argv)
  92 {
  93         argv0 = argv[0];
  94
  95         struct timespec ti;
  96         char buf[MAX_LEN];
  97
  98         opt_parse(argc, argv);
  99
 100         signal(SIGPIPE, SIG_IGN);  /* Handled in loop */
 101
 102         memset(buf, '\0', MAX_LEN);
 103         ti = timespec_of_float(opt_interval);
 104         loop(
 105             &ti,
 106             fifo_name,
 107             buf,
 108             (SENSOR_FUN_T)    get_time,
 109             (SENSOR_PARAMS_T) opt_fmt
 110         );
 111         return EXIT_SUCCESS;
 112 }