add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/animals.c

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+/*  animals - guessing game	Authors: Terrence W. Holm & Edwin L. Froese */
+
+#include <sys/types.h>
+#include <string.h>
+#include <signal.h>
+#include <sgtty.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#define  ANIMALS	"/usr/lib/animals"
+#define  DEFAULT_ANIMAL	"beaver"
+#define  MAX_NODES	999	/* Enough for 500 animals  */
+#define  MAX_LINE	90
+
+void Abort();
+char *Get_Animal();
+char *Get_Question();
+char *A_or_An();
+char *Alloc();
+
+struct node {
+  int question;
+  char *text;
+  int yes;
+  int no;
+} animals[MAX_NODES];
+
+int count = 0;
+struct sgttyb old_tty_mode;
+
+
+main(argc, argv)
+int argc;
+char *argv[];
+
+{
+  char *animal_file = ANIMALS;
+
+  if (argc > 2) {
+	fprintf(stderr, "Usage:  %s  [ data_base ]\n", argv[0]);
+	exit(1);
+  }
+  if (argc == 2) animal_file = argv[1];
+
+  ioctl(0, TIOCGETP, &old_tty_mode);
+
+  signal(SIGINT, Abort);
+  signal(SIGQUIT, Abort);
+
+  if (access(animal_file, R_OK) == 0)
+	Read_Animals(animal_file);
+  else {
+	animals[0].question = 0;
+	animals[0].text = DEFAULT_ANIMAL;
+	count = 1;
+  }
+
+  while (Ask("\nAre you thinking of an animal?")) {
+	int i = 0;
+
+	while (1) {
+		if (animals[i].question) {
+			if (Ask(animals[i].text))
+				i = animals[i].yes;
+			else
+				i = animals[i].no;
+		} else {
+			printf("Were you thinking of %s %s",
+			 A_or_An(animals[i].text), animals[i].text);
+
+			if (Ask("?")) printf("I knew it!\n");
+
+			else {
+				/* Insert a new question and animal name  */
+
+				if (count + 2 > MAX_NODES)
+					Error("Too many animal names");
+
+				animals[count].question = 0;
+				animals[count].text = animals[i].text;
+				++count;
+
+				animals[count].question = 0;
+				printf("What animal were you thinking of? ");
+				animals[count].text = Get_Animal();
+				++count;
+
+				animals[i].question = 1;
+				printf("What question would distinguish %s %s from\n%s %s? ",
+				       A_or_An(animals[count - 2].text), animals[count - 2].text,
+				       A_or_An(animals[count - 1].text), animals[count - 1].text);
+
+				animals[i].text = Get_Question();
+
+				printf("For %s %s, the answer would be",
+				       A_or_An(animals[count - 1].text), animals[count - 1].text);
+
+				if (Ask("?")) {
+					animals[i].yes = count - 1;
+					animals[i].no = count - 2;
+				} else {
+					animals[i].yes = count - 2;
+					animals[i].no = count - 1;
+				}
+			}
+
+			break;
+		}
+	}			/* End while ( 1 )  */
+
+  }
+
+
+  ioctl(0, TIOCSETP, &old_tty_mode);
+
+  printf("\nThank you for playing \"animals\".\n");
+  printf("The animal data base is now being updated.\n");
+
+  Write_Animals(animal_file);
+
+  sleep(1);
+  printf("\nBye.\n");
+
+  exit(0);
+}
+
+
+/*  Reading and writing the animal data base */
+
+
+Read_Animals(animal_file)
+char *animal_file;
+
+{
+  FILE *f;
+  char buffer[MAX_LINE];
+
+  if ((f = fopen(animal_file, "r")) == NULL)
+	Error("Can not open animal data base");
+
+  while (fgets(buffer, MAX_LINE, f) != NULL) {
+	int string_length;
+	char *string;
+
+	buffer[strlen(buffer) - 1] = '\0';
+
+	swab(buffer, buffer, strlen(buffer));
+
+	if (buffer[0] == 'q') {
+		char *end = strchr(buffer, '?');
+		string_length = end - buffer;
+		animals[count].question = 1;
+		sscanf(end+1, "%d:%d",&animals[count].yes,&animals[count].no);
+	} else {
+		animals[count].question = 0;
+		string_length = strlen(buffer) - 1;
+	}
+
+	string = Alloc(string_length + 1);
+
+	string[0] = '\0';
+	strncat(string, buffer + 1, string_length);
+
+	animals[count].text = string;
+
+	count++;
+  }
+
+  fclose(f);
+}
+
+
+Write_Animals(animal_file)
+char *animal_file;
+
+{
+  FILE *f;
+  int i;
+  char buffer[MAX_LINE];
+
+  if ((f = fopen(animal_file, "w")) == NULL)
+	Error("Can not write animal data base");
+
+  for (i = 0; i < count; ++i) {
+	if (animals[i].question) sprintf(buffer, "q%s%d:%d", animals[i].text,
+			animals[i].yes, animals[i].no);
+	else
+		sprintf(buffer, "a%s", animals[i].text);
+
+	/* Make the data base a bit difficult to read  */
+	swab(buffer, buffer, strlen(buffer));
+	fprintf(f, "%s\n", buffer);
+  }
+
+  fclose(f);
+  chmod(animal_file, 0666);
+}
+
+
+/*  Reading data from the user */
+int Ask(question)
+char *question;
+{
+  struct sgttyb new_tty_mode;
+  int response;
+
+  new_tty_mode = old_tty_mode;
+  new_tty_mode.sg_flags |= CBREAK;
+  ioctl(0, TIOCSETP, &new_tty_mode);
+
+  printf("%s ", question);
+
+  while ((response = getchar()) != 'y' && response != 'n')
+	printf("\n%s [yn]?", question);
+  putchar('\n');
+  ioctl(0, TIOCSETP, &old_tty_mode);
+  if (response == 'y')
+	return(1);
+  else
+	return(0);
+}
+
+
+char *Get_Animal()
+{
+  char s[MAX_LINE];
+  char *text;
+  int text_length;
+
+  fgets(s, MAX_LINE, stdin);
+  text_length = strlen(s);
+  text = Alloc(text_length);
+  text[0] = '\0';
+  strncat(text, s, text_length - 1);
+  return(text);
+}
+
+
+char *Get_Question()
+{
+  char s[MAX_LINE];
+  char *end;
+  char *text;
+
+  fgets(s, MAX_LINE, stdin);
+
+  /* Capitalize the first letter  */
+  if (islower(s[0])) s[0] = toupper(s[0]);
+
+  /* Make sure the question ends with a '?'  */
+  if ((end = strchr(s, '?')) == NULL)
+	s[strlen(s) - 1] = '?';
+  else
+	end[1] = '\0';
+
+  text = Alloc(strlen(s) + 1);
+  strcpy(text, s);
+  return(text);
+}
+
+
+/*  Utility routines */
+char *A_or_An(word)
+char *word;
+{
+  if (strchr("aeiouAEIOU", word[0]) == NULL)
+	return("a");
+  else
+	return("an");
+}
+
+
+char *Alloc(size)
+int size;
+{
+  char *malloc();
+  char *memory;
+
+  if ((memory = malloc(size)) == NULL)
+	Error("No room in memory for all the animals");
+
+  return(memory);
+}
+
+
+void Abort()
+{
+  ioctl(0, TIOCSETP, &old_tty_mode);
+
+  printf("\nThank you for playing \"animals\".\n");
+  printf("Since you aborted, the animal data base will not be updated.\n");
+  sleep(1);
+  printf("\nBye.\n");
+  exit(1);
+}
+
+
+Error(message)
+char *message;
+{
+  ioctl(0, TIOCSETP, &old_tty_mode);
+  fprintf(stderr, "Error: %s\n", message);
+  exit(1);
+}