#include <fcntl.h>
#include <stdio.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

int entry_kat(int argc, char **argv) {
  if (argc == 2 && strcmp(argv[1], "-h") == 0) {
    fprintf(stderr, "Gebruik: kat [BESTAND]...\n"
                    "\n"
                    "Schakel BESTAND(en) aaneen naar standaard uitvoer..\n");
    return 0;
  }

  for (int i = 1; i < argc; i++) {
    const char *fname = argv[i];
    int fd = open(fname, O_RDONLY);

    struct stat sb;
    if (fstat(fd, &sb) == -1) {
      fprintf(stderr, "Kon bestand niet lezen\n");
      return 0;
    }

    char *addr = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
    if (addr == MAP_FAILED) {
      fprintf(stderr, "Kon bestand niet kaarten\n");
      return 0;
    }

    for (size_t i = 0; i < sb.st_size; i++) {
      putchar(addr[i]);
    }

    munmap(addr, sb.st_size);
    close(fd);
  }

  return 0;
}