khatus_lib_sensor.c

   1 #include <errno.h>
   2 #include <fcntl.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7
   8 #include "khatus_lib_log.h"
   9 #include "khatus_lib_sensor.h"
  10 #include "khatus_lib_time.h"
  11
  12 void
  13 loop(
  14     struct timespec *ti,
  15     char *fifo,
  16     char *buf,
  17     int fun(char *, void *),
  18     void *params)
  19 {
  20         int fd = -1;
  21         int w  = -1;  /* written */
  22         int r  = -1;  /* remaining */
  23         int i  = -1;  /* buffer position */
  24
  25         for (;;) {
  26                 debug("openning \"%s\"\n", fifo);
  27                 fd = open(fifo, O_WRONLY);
  28                 if (fd < 0)
  29                         fatal("Failed to open FIFO file: \"%s\". Error: %s\n",
  30                             fifo,
  31                             strerror(errno));
  32                 debug("openned. fd: %d\n", fd);
  33                 r = fun(buf, params);
  34                 buf[r] = END_OF_MESSAGE;
  35                 for (i = 0; (w = write(fd, buf + i++, 1)) && r; r--)
  36                         ;
  37                 if (w < 0)
  38                         switch (errno) {
  39                         case EPIPE:
  40                                 error("Broken pipe. Msg buf: %s\n", buf);
  41                                 break;
  42                         default:
  43                                 fatal(
  44                                     "Failed to write to %s. "
  45                                     "Err num: %d, Err msg: %s\n",
  46                                     fifo,
  47                                     errno,
  48                                     strerror(errno));
  49                         }
  50                 if (close(fd) < 0)
  51                         fatal("Failed to close %s. Err num: %d, Err msg: %s\n",
  52                             fifo,
  53                             errno,
  54                             strerror(errno));
  55                 fd = -1;
  56                 debug("closed. fd: %d\n", fd);
  57                 snooze(ti);
  58         }
  59 }