Hold a lock while appending

[tl-append] / common.c

#define _POSIX_C_SOURCE 2
#include "common.h"

#include <stdio.h>
#include <stdlib.h>

const char *const FILENAME = "tl.log";

void die(const char *message) {
  fputs(message, stderr);
  fputc('\n', stderr);
  exit(1);
}

void die_err(const char *message) {
  perror(message);
  exit(1);
}

const char *encode_time(time_t t) {
  struct tm tm;
  localtime_r(&t, &tm);
  const size_t size = 20;
  char *out = (char *)malloc(size);
  if (strftime(out, size, "%Y %m %d %H %M %S", &tm) != size - 1)
    die("Couldn't format time");
  return out;
}