x5/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_time.h"
  14
  15 #define usage(...) {print_usage(); fprintf(stderr, "Error:\n    " __VA_ARGS__); exit(EXIT_FAILURE);}
  16
  17 #define MAX_LEN 20
  18 #define END_OF_MESSAGE '\n'
  19
  20 char *argv0;
  21
  22 void
  23 print_usage()
  24 {
  25         printf(
  26             "%s: [OPT ...] FIFO\n"
  27             "\n"
  28             "FIFO = string    # path to fifo file\n"
  29             "OPT = -i int     # interval\n"
  30             "    | -f string  # format string\n"
  31             "    | -h         # help message (i.e. what you're reading now :) )\n",
  32             argv0);
  33 }
  34
  35 int
  36 main(int argc, char **argv)
  37 {
  38         argv0 = argv[0];
  39
  40         double opt_interval = 1.0;
  41         char *opt_fmt = "%a %b %d %H:%M:%S";
  42
  43         time_t t;
  44         struct timespec ti;
  45         char buf[MAX_LEN];
  46         char c;
  47
  48         char *fifo_name;
  49         int   fifo_fd = -1;
  50
  51         int n = 0;  /* written */
  52         int r = 0;  /* remaining */
  53         int i = 0;  /* buffer position */
  54
  55         signal(SIGPIPE, SIG_IGN);  /* Handling manually */
  56
  57         memset(buf, '\0', MAX_LEN);
  58         while ((c = getopt(argc, argv, "f:i:h")) != -1)
  59                 switch (c) {
  60                 case 'f':
  61                         opt_fmt = calloc(strlen(optarg), sizeof(char));
  62                         strcpy(opt_fmt, optarg);
  63                         break;
  64                 case 'i':
  65                         opt_interval = atof(optarg);
  66                         break;
  67                 case 'h':
  68                         print_usage();
  69                         return 0;
  70                 case '?':
  71                         if (optopt == 'f' || optopt == 'i')
  72                                 fprintf(stderr,
  73                                         "Option -%c requires an argument.\n",
  74                                         optopt);
  75                         else if (isprint(optopt))
  76                                 fprintf (stderr,
  77                                         "Unknown option `-%c'.\n",
  78                                         optopt);
  79                         else
  80                                 fprintf(stderr,
  81                                         "Unknown option character `\\x%x'.\n",
  82                                         optopt);
  83                         return 1;
  84                 default:
  85                         assert(0);
  86                 }
  87         fifo_name = argv[optind];
  88         debug("fifo_name: %s\n", fifo_name);
  89         if (!fifo_name)
  90                 usage("No filename was provided\n");
  91         ti = timespec_of_float(opt_interval);
  92         for (;;) {
  93                 debug("openning \"%s\"\n", fifo_name);
  94                 fifo_fd = open(fifo_name, O_WRONLY);
  95                 if (fifo_fd < 0)
  96                         fatal("Failed to open FIFO file: \"%s\". Error: %s\n",
  97                             fifo_name,
  98                             strerror(errno));
  99                 debug("openned. fd: %d\n", fifo_fd);
 100                 t = time(NULL);
 101                 strftime(buf, MAX_LEN, opt_fmt, localtime(&t));
 102                 r = strlen(buf);
 103                 buf[r] = END_OF_MESSAGE;
 104                 for (i = 0; (n = write(fifo_fd, buf + i++, 1)) && r; r--)
 105                         ;
 106                 if (n < 0)
 107                         fatal("Failed to write to %s. Err num: %d, Err msg: %s\n",
 108                             fifo_name,
 109                             errno,
 110                             strerror(errno));
 111                 if (close(fifo_fd) < 0)
 112                         fatal("Failed to close %s. Err num: %d, Err msg: %s\n",
 113                             fifo_name,
 114                             errno,
 115                             strerror(errno));
 116                 fifo_fd = -1;
 117                 debug("closed. fd: %d\n", fifo_fd);
 118                 snooze(&ti);
 119         }
 120         return EXIT_SUCCESS;
 121 }