test-instr.c

/*
   american fuzzy lop++ - a trivial program to test the build
   --------------------------------------------------------
   Originally written by Michal Zalewski
   Copyright 2014 Google Inc. All rights reserved.
   Copyright 2019-2020 AFLplusplus Project. All rights reserved.
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at:
     http://www.apache.org/licenses/LICENSE-2.0
 */

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

int main(int argc, char **argv) {

  int   fd = 0;
  char  buff[8];
  char *buf = buff;

  // we support command line parameter and stdin
  if (argc == 2) {

    buf = argv[1];
    printf("Input %s - ", buf);

  } else {

    if (argc >= 3 && strcmp(argv[1], "-f") == 0)
      if ((fd = open(argv[2], O_RDONLY)) < 0) {

        fprintf(stderr, "Error: unable to open %s\n", argv[2]);
        exit(-1);

      }

    if (read(fd, buf, sizeof(buf)) < 1) {

      printf("Hum?\n");
      return 1;

    }

  }

  // we support three input cases (plus a 4th if stdin is used but there is no
  // input)
  if (buf[0] == '0')
    printf("Looks like a zero to me!\n");
  else if (buf[0] == '1')
    printf("Pretty sure that is a one!\n");
  else
    printf("Neither one or zero? How quaint!\n");

  return 0;

}