/*
 * Program to show how various string handling calls behave when given a nul ('\0') to find in a
 * string.
 *
 * Author: James Hunt (james.hunt-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org)
 */

/* for strchrnul() */
#define _GNU_SOURCE

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <assert.h>

int
main(int argc, char *argv[])
{
  size_t len;
  char c;
  char *sp;
  char string[] = "foo bar. Hello, world!";

  len = strlen(string);
  fprintf(stderr, "string='%s' (len=%d, start=%p, end=%p ['%c'], nul=%p ['%c'])\n\n",
      string, (int)len,
      string,
      string+len-1,
      *(string+len-1),
      string+len,
      *(string+len));

  c  = 'f';
  sp = "f";
  fprintf(stderr, "strchr     ('%s', '%c')              returned %p\n", string, c, strchr(string, c));
  fprintf(stderr, "memchr     ('%s', '%c', strlen(s))   returned %p\n", string, c, memchr(string, c, strlen(string)));
  fprintf(stderr, "memchr     ('%s', '%c', 1+strlen(s)) returned %p\n", string, c, memchr(string, c, 1+strlen(string)));
  fprintf(stderr, "strrchr    ('%s', '%c')              returned %p\n", string, c, strrchr(string, c));
  fprintf(stderr, "strchrnul  ('%s', '%c')              returned %p\n", string, c, strchrnul(string, c));
  fprintf(stderr, "strstr     ('%s', '%s')              returned %p\n", string, sp, strstr(string, sp));

  fputc ('\n', stderr);

  c  = 'o';
  sp = "o";
  fprintf(stderr, "strchr     ('%s', '%c')              returned %p\n", string, c, strchr(string, c));
  fprintf(stderr, "memchr     ('%s', '%c', strlen(s))   returned %p\n", string, c, memchr(string, c, strlen(string)));
  fprintf(stderr, "memchr     ('%s', '%c', 1+strlen(s)) returned %p\n", string, c, memchr(string, c, 1+strlen(string)));
  fprintf(stderr, "strrchr    ('%s', '%c')              returned %p\n", string, c, strrchr(string, c));
  fprintf(stderr, "strchrnul  ('%s', '%c')              returned %p\n", string, c, strchrnul(string, c));
  fprintf(stderr, "strstr     ('%s', '%s')              returned %p\n", string, sp, strstr(string, sp));

  fputc ('\n', stderr);

  c  = '!';
  sp = "!";
  fprintf(stderr, "strchr     ('%s', '%c')              returned %p\n", string, c, strchr(string, c));
  fprintf(stderr, "memchr     ('%s', '%c', strlen(s))   returned %p\n", string, c, memchr(string, c, strlen(string)));
  fprintf(stderr, "memchr     ('%s', '%c', 1+strlen(s)) returned %p\n", string, c, memchr(string, c, 1+strlen(string)));
  fprintf(stderr, "strrchr    ('%s', '%c')              returned %p\n", string, c, strrchr(string, c));
  fprintf(stderr, "strchrnul  ('%s', '%c')              returned %p\n", string, c, strchrnul(string, c));
  fprintf(stderr, "strstr     ('%s', '%s')              returned %p\n", string, sp, strstr(string, sp));

  fputc ('\n', stderr);

  c  = '\0';
  sp = "";
  fprintf(stderr, "strchr     ('%s', '%c')              returned %p\n", string, c, strchr(string, c));
  fprintf(stderr, "memchr     ('%s', '%c', strlen(s))   returned %p\n", string, c, memchr(string, c, strlen(string)));
  fprintf(stderr, "memchr     ('%s', '%c', 1+strlen(s)) returned %p\n", string, c, memchr(string, c, 1+strlen(string)));
  fprintf(stderr, "strrchr    ('%s', '%c')              returned %p\n", string, c, strrchr(string, c));
  fprintf(stderr, "strchrnul  ('%s', '%c')              returned %p\n", string, c, strchrnul(string, c));
  fprintf(stderr, "strstr     ('%s', '%s')              returned %p\n", string, sp, strstr(string, sp));
  sp = "\0";
  fprintf(stderr, "strstr     ('%s', '%s')              returned %p\n", string, sp, strstr(string, sp));

  /* XXX: not valid calls */
#if 0
  fprintf(stderr, "strstr     (NULL, '%s') returned %p\n", "X", strstr(NULL, "X"));
  fprintf(stderr, "strstr     (NULL, '%s') returned %p\n", "\0", strstr(NULL, "\0"));
  fprintf(stderr, "strstr     ('%s', NULL) returned %p\n", string, strstr(string, NULL));
  /* XXX: core dumps */
#endif

  fputc ('\n', stderr);

  c  = 'Z';
  sp = "Z";
  fprintf(stderr, "strchr     ('%s', '%c')              returned %p\n", string, c, strchr(string, c));
  fprintf(stderr, "memchr     ('%s', '%c', strlen(s))   returned %p\n", string, c, memchr(string, c, strlen(string)));
  fprintf(stderr, "memchr     ('%s', '%c', 1+strlen(s)) returned %p\n", string, c, memchr(string, c, 1+strlen(string)));
  fprintf(stderr, "strrchr    ('%s', '%c')              returned %p\n", string, c, strrchr(string, c));
  fprintf(stderr, "strchrnul  ('%s', '%c')              returned %p\n", string, c, strchrnul(string, c));
  fprintf(stderr, "strstr     ('%s', '%s')              returned %p\n", string, sp, strstr(string, sp));

  exit(EXIT_SUCCESS);
}