x5/khatus_sensor_time.c

   1 #include <assert.h>
   2 #include <ctype.h>
   3 #include <errno.h>
   4 #include <signal.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <time.h>
   9 #include <unistd.h>
  10
  11 #include "khlib_log.h"
  12 #include "khlib_time.h"
  13
  14 #define usage(...) {print_usage(); fprintf(stderr, "Error:\n    " __VA_ARGS__); exit(EXIT_FAILURE);}
  15
  16 #define MAX_LEN 20
  17 #define END_OF_MESSAGE '\n'
  18
  19 char *argv0 = NULL;
  20
  21 double opt_interval = 1.0;
  22 char *opt_fmt = "%a %b %d %H:%M:%S";
  23
  24 void
  25 print_usage()
  26 {
  27         printf(
  28             "%s: [OPT ...]\n"
  29             "\n"
  30             "OPT = -i int     # interval\n"
  31             "    | -f string  # format string\n"
  32             "    | -h         # help message (i.e. what you're reading now :) )\n",
  33             argv0);
  34 }
  35
  36 void
  37 opt_parse(int argc, char **argv)
  38 {
  39         char c;
  40
  41         while ((c = getopt(argc, argv, "f:i:h")) != -1)
  42                 switch (c) {
  43                 case 'f':
  44                         opt_fmt = calloc(strlen(optarg), sizeof(char));
  45                         strcpy(opt_fmt, optarg);
  46                         break;
  47                 case 'i':
  48                         opt_interval = atof(optarg);
  49                         break;
  50                 case 'h':
  51                         print_usage();
  52                         exit(EXIT_SUCCESS);
  53                 case '?':
  54                         if (optopt == 'f' || optopt == 'i')
  55                                 fprintf(stderr,
  56                                         "Option -%c requires an argument.\n",
  57                                         optopt);
  58                         else if (isprint(optopt))
  59                                 fprintf (stderr,
  60                                         "Unknown option `-%c'.\n",
  61                                         optopt);
  62                         else
  63                                 fprintf(stderr,
  64                                         "Unknown option character `\\x%x'.\n",
  65                                         optopt);
  66                         exit(EXIT_FAILURE);
  67                 default:
  68                         assert(0);
  69                 }
  70 }
  71
  72 int
  73 main(int argc, char **argv)
  74 {
  75         argv0 = argv[0];
  76
  77         time_t t;
  78         struct timespec ti;
  79         char buf[MAX_LEN];
  80
  81         opt_parse(argc, argv);
  82         ti = khlib_timespec_of_float(opt_interval);
  83         khlib_debug("opt_fmt: \"%s\"\n", opt_fmt);
  84         khlib_debug("opt_interval: %f\n", opt_interval);
  85         khlib_debug("ti: {tv_sec = %ld, tv_nsec = %ld}\n",ti.tv_sec,ti.tv_nsec);
  86         memset(buf, '\0', MAX_LEN);
  87         signal(SIGPIPE, SIG_IGN);
  88
  89         for (;;) {
  90                 t = time(NULL);
  91                 strftime(buf, MAX_LEN, opt_fmt, localtime(&t));
  92                 puts(buf);
  93                 fflush(stdout);
  94                 khlib_sleep(&ti);
  95         }
  96         return EXIT_SUCCESS;
  97 }