Category : C Source Code
Archive   : BTREE2.ZIP
Filename : EXAMPLE.C

/* **** EXAMPLE.C ****
* This program is an example of how to use Ray Swartz's btree library.
* To use this program, a key file must be initialized first.
* This program maintains no data entries besides the keys entered
* into the key file.
*
*
*
*
* Author: Ray Swartz
* P.O. Box 2528
* Santa Cruz, Calif. 95063
* Last Modified: 4/28/85
*
* ANY USE OF THESE LIBRARY ROUTINES EITHER PERSONAL OR COMMERCIAL
* IS ALLOWED UPON THE CONDITION THAT THE USER IDENTIFY THEM
* AS BEING USED IN THE PROGRAM. IDENTIFYING INFORMATION MUST
* APPEAR IN THE PROGRAM DOCUMENTATION OR ON THE TERMINAL SCREEN.
*
* #################################
* # UNATTRIBUTED USE IS FORBIDDEN #
* #################################
*
*/



#include "stdio.h"
#include "btree.h"


main()
{
extern char instr[]; /* general input string */

struct keyinfo header; /* keyfile being used */
struct node current_node; /* stores current node's information */
char *key1; /* key to search for */
char *malloc();
int choice; /* user's menu choice */
long node_nbr; /* number of current_ node */
long pop_right_stack(), pop_left_stack();
FILE *open_keyfile();

printf("Key file to use: ");
gets(instr);
header.file = open_keyfile(instr, &header);
/* must allocate space for the key pointers */
key1 = malloc(header.keylength + 1);
current_node.key = malloc(header.keylength + 1);
cursor(1,1);
CLEAR_END_OF_PAGE
while ((choice = main_prompt("Choice: ")) != QUIT) {
if (choice == FIND) {
cursor(1,1);
CLEAR_END_OF_PAGE
get_key("Key to Find: ", key1, &header);
if(find_key(key1, &node_nbr, ¤t_node, &header)==NOT_FOUND) {
print_msg("Key not found");
show_rec(¤t_node); /* show key node "found" */
}
else if(node_nbr == END) /* no undeleted node found */
printf("node_nbr == END\n"); /* tree "empty" */
else
show_rec(¤t_node); /* exact match found */
}
else if (choice == NEXT) {
cursor(1,1);
CLEAR_END_OF_PAGE
switch (get_next(&node_nbr, ¤t_node, &header)) {
case(NO):
continue; /* no current node */
break;
case(YES):
show_rec(¤t_node); /* found one */
break;
case(AT_END):
print_msg("At end of file");
show_rec(¤t_node);
}
}
else if (choice == PREVIOUS) {
cursor(1,1);
CLEAR_END_OF_PAGE
switch (get_previous(&node_nbr, ¤t_node, &header)) {
case(NO):
continue; /* no current node */
break;
case(YES):
show_rec(¤t_node); /* found one */
break;
case(AT_END):
print_msg("At end of file");
show_rec(¤t_node);
}
}
else if (choice == INSERT) {
cursor(1,1);
CLEAR_END_OF_PAGE
enter_data(¤t_node, &header); /* get key to insert */
insert(current_node.key, header.next_avail, &header);
}
else if (choice == DELETE) {
if (yes_or_no("Delete this record? (y/n) ") == YES)
delete_key(node_nbr, ¤t_node, &header);
}
} /* QUIT chosen by user */
close_keyfile(&header);
exit(0);
}


show_rec(current_node)
struct node *current_node;
{
cursor(1,1);
CLEAR_END_OF_PAGE
print_node(current_node);
return;
}


enter_data(current_node, fileinfo)
struct keyinfo *fileinfo;
struct node *current_node;
{
extern char instr[];

printf("Enter a key: ");
gets(instr);
strncpy(current_node->key, instr, fileinfo->keylength);
current_node->key[fileinfo->keylength] = '\0';
return;
}