x5/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(struct timespec *ti, char *fifo, char *buf, int fun(char *))
  14 {
  15         int fd = -1;
  16         int w  = -1;  /* written */
  17         int r  = -1;  /* remaining */
  18         int i  = -1;  /* buffer position */
  19
  20         for (;;) {
  21                 debug("openning \"%s\"\n", fifo);
  22                 fd = open(fifo, O_WRONLY);
  23                 if (fd < 0)
  24                         fatal("Failed to open FIFO file: \"%s\". Error: %s\n",
  25                             fifo,
  26                             strerror(errno));
  27                 debug("openned. fd: %d\n", fd);
  28                 r = fun(buf);
  29                 buf[r] = END_OF_MESSAGE;
  30                 for (i = 0; (w = write(fd, buf + i++, 1)) && r; r--)
  31                         ;
  32                 if (w < 0)
  33                         switch (errno) {
  34                         case EPIPE:
  35                                 error("Broken pipe. Msg buf: %s\n", buf);
  36                                 break;
  37                         default:
  38                                 fatal(
  39                                     "Failed to write to %s. "
  40                                     "Err num: %d, Err msg: %s\n",
  41                                     fifo,
  42                                     errno,
  43                                     strerror(errno));
  44                         }
  45                 if (close(fd) < 0)
  46                         fatal("Failed to close %s. Err num: %d, Err msg: %s\n",
  47                             fifo,
  48                             errno,
  49                             strerror(errno));
  50                 fd = -1;
  51                 debug("closed. fd: %d\n", fd);
  52                 snooze(ti);
  53         }
  54 }