util.c

/** \file
 * Various utility functions
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <fcntl.h>
#include <termios.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <inttypes.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include "util.h"

/** Write all the bytes to a fd, even if there is a brief interruption.
 * \return number of bytes written or -1 on any fatal error.
 */
ssize_t write_all(const int fd, const void *const buf_ptr, const size_t len) {
  const uint8_t *const buf = buf_ptr;
  size_t offset = 0;

  while (offset < len) {
    const ssize_t rc = write(fd, buf + offset, len - offset);
    if (rc < 0) {
      if (errno == EAGAIN)
        continue;
      return -1;
    }

    if (rc == 0)
      return -1;

    offset += rc;
  }

  return len;
}

int serial_open(const char *const dev) {
  const int fd = open(dev, O_RDWR | O_NONBLOCK | O_NOCTTY, 0666);
  if (fd < 0)
    return -1;

  // Disable modem control signals
  struct termios attr;
  tcgetattr(fd, &attr);
  attr.c_cflag |= CLOCAL | CREAD;
  attr.c_oflag &= ~OPOST;
  tcsetattr(fd, TCSANOW, &attr);

  return fd;
}

void hexdump(FILE *const outfile, const void *const buf, const size_t len) {
  const uint8_t *const p = buf;

  for (size_t i = 0; i < len; i++) {
    if (i % 8 == 0)
      fprintf(outfile, "%s%04zu:", i == 0 ? "" : "\n", i);
    fprintf(outfile, " %02x", p[i]);
  }

  fprintf(outfile, "\n");
}