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

int main(int argc, char *argv[])
{
  char buf[BUFSIZ];
  int fin,nchar;
  char msg_stdout[]="Esta es la salida estandar\n";
  char msg_stderr[]="Esta es la salida de errores\n";

  if (argc < 2) {
    fprintf(stderr,"Usage: %s input_file\n",argv[0]);
    exit(1);
  }

  write(STDOUT_FILENO,msg_stdout,strlen(msg_stdout));
  write(STDERR_FILENO,msg_stderr,strlen(msg_stderr));

  if ((fin=open(argv[1],O_RDONLY)) == -1) {
    fprintf(stderr,"No se puede abrir el fichero %s\n",argv[1]);
    exit(1);
  }

  nchar=read(fin, buf, sizeof(buf));
  if (nchar > 0)
    write(STDOUT_FILENO, buf, nchar);

  exit(0);
    
}