Help me remember C!

[Nodrog]

#include <stdio.h>
#include <string.h>
#include "struct.h"
#define ARRAY_SIZE 100
#define WELCOME_TEXT "Welcome to the person database!\n\n"
#define PROMPT "Would you like to [A]dd a record, [S]earch for a record, or [Q]uit? "
#define ERROR "You didnt enter a valid option"
#define PRINT_ALL "\nHere are a list of all people in database:\n\n"
#define SEARCH_TEXT "Would you like to search by [F]irst or [L]ast name? "
#line 1

void print_person(PERSON *p);
PERSON search_first_name(char* name);
PERSON search_last_name(char* name);
PERSON search_records();
void add_person();
void print_all();

PERSON records[ARRAY_SIZE];
int number_of_records = 0;

int main() {
	char input;
	printf(WELCOME_TEXT);
	while (input != 'Q') {
		printf(PROMPT);
		scanf("%c", &input);
		if (input >= 'a' && input <= 'z') {input -= 32;}
		if (input == 'A') {add_person();}
		else if (input == 'S') {search_records();}
		else if (input != 'Q') {printf(ERROR);}
	}
	print_all();
}

void print_person(PERSON *ptr) {
	printf("First name: %s\n", ptr->first_name);
	printf("Last name: %s\n", ptr->last_name);
	printf("Phone Number: %s\n", ptr->phone_number);
	printf("Age: %d\n", ptr->age);
}

void add_person() {
	PERSON temp;
	printf("\nFirst Name - ");
	scanf("%s", &(temp.first_name));
	printf("Last Name - ");
	scanf("%s", &(temp.last_name));
	printf("Phone Number - ");
	scanf("%s", &(temp.phone_number));
	printf("Age - ");
	scanf("%d", &(temp.age));
	
	records[number_of_records++] = temp;
}

PERSON search_first_name(char* name) {
	int i;
	printf("woah");
	for (i = 0 ; i != number_of_records ; i++) {
		if (strstr(records[i].first_name, name)) {return records[i];}
	}
}

PERSON search_last_name(char* name) {
	int i;
	for (i = 0 ; i != number_of_records ; i++) {
		if (strstr(records[i].last_name, name)) {return records[i];}
	}
}


PERSON search_records() {
	char type;
	char* search_text;
	PERSON result;

	printf(SEARCH_TEXT);
	scanf("%c", &type);
	//printf("Input string to search for ");
	//scanf("%s", search_text);

	if (type >= 'a' && type <= 'z') {type -= 32;}
	if (type == 'F') {result = search_first_name(search_text);}
	else if (type == 'L') {result = search_last_name(search_text);}

	print_person(&result);
}

void print_all() {
	int i;
	PERSON *current;
	printf(PRINT_ALL);
	for (i = 0 ; i != number_of_records ; i++) {
		current = &records[i];
		print_person(current);
		printf("\n");
	}
}

This produces the following output:


Welcome to the person database!

Would you like to [A]dd a record, [S]earch for a record, or [Q]uit? a

First Name - gordon
Last Name - ross
Phone Number - 342343
Age - 19
Would you like to [A]dd a record, [S]earch for a record, or [Q]uit? You didnt enter a valid optionWould you like to [A]dd a record, [S]earch for a record, or [Q]uit? s
Would you like to search by [F]irst or [L]ast name? First name: e
Last name: ¿üöÿ¿òÑ@ð÷ÿ¿
Phone Number÷ÿ¿
Age: 875757568
Would you like to [A]dd a record, [S]earch for a record, or [Q]uit? q



Note the repetition of text in the prompt. Also, I never typed the 'e' that is in bold. When I press 'S' for search, the program somehow reads an 'e' from stdin, that shouldnt be there.

What have I done wrong?

[meglamaniac]

Forgotten to comment your program for a start.
Bad Nod! Bad!

As for anything else - I'm not too sure.
This looks like a more advanced version of the C coursework I'm working on at the moment (we have to create a simple "phonebook" type database to certain specifications set by the lecturer, but are not required to include a search) but you're doing it a very different way.

Incidentally, why are you #define-ing the messages rather than just storing them as strings? I'm not saying it's wrong - I'm just interested why, as you have considerably more experience than me...

[Nodrog]

Originally posted by meglamaniac

Incidentally, why are you #define-ing the messages rather than just storing them as strings? I'm not saying it's wrong - I'm just interested why, as you have considerably more experience than me...

I doubt that, I just started learning C today, although I did get up to just past the hello world stage a few months ago. Im using #defines because preprocessors are cool. How are you doing it out of interest, given its pretty much the same thing you're doing.

[meglamaniac]

I don't have the code available here (I do have access to the network drive but the muppets don't map what you store on it under linux to windows so it's like having two seperate drives even though they're the same space).
I've only got up to the loading of records and the listing of them (I've only had like 3 hours on it).
It's also not pure C since they've decided to try and make it 'easier' for the newbies by using some c++, especially for i/o (hello cout,cin,fstream, etc).

it basicly goes:

<includes>
<global variables>
<fuction prototypes>

main {
  switch to do a menu
     case to load records
     case to list records
  while condition to restart menu or quit
}

load records function {
  opens file
  loads contents into struct array
  error checks etc
}

display records function {
   error checking stuff (are the any records loaded etc)
   loops through stuct array listing records
}

Theres more to it than that, but thats the best I can give you atm.

[Epcylon]

Originally posted by Nodrog
I doubt that, I just started learning C today, although I did get up to just past the hello world stage a few months ago. Im using #defines because preprocessors are cool. How are you doing it out of interest, given its pretty much the same thing you're doing.

Been a while since I did any c programming (why bother with low-level stuff when you can achive better results with python or java ) but iirc there is a significant difference between using defines and strings.

Could be this gets fixed by your compiler during optimization, but when you use defines, the string gets inserted in the code wherever the defined constant is used, while if you use a string constant to hold it, the string itself is only stored 1 place, and a reference to that location is used every time you use the string.

Now, when it comes to the rest of your code, scanf is evil! Use fgets instead, and I'm willing to bet you get better results almost instantly... (I could go dig up the link to why scanf is evil, but I'm tired and don't remember where I put it... )

There's probably more, but with the lack of comments and me not having coded c in years...

[MT]

its not right, but its more right ..

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define ARRAY_SIZE 100
#define WELCOME_TEXT "Welcome to the person database!\n\n"
#define PROMPT "Would you like to [A]dd a record, [S]earch for a record, or [Q]uit? "
#define ERROR "You didnt enter a valid option"
#define PRINT_ALL "\nHere are a list of all people in database:\n\n"
#define SEARCH_TEXT "Would you like to search by [F]irst or [L]ast name? "

typedef struct person {  
  char first_name[15];  
  char last_name[15];  
  char phone_number[20];  
  int age;}
  PERSON;

void print_person(PERSON*);
int search_first_name(PERSON*,char*);
int search_last_name(PERSON*,char*);
void search_records();
void add_person();
void print_all();

PERSON *records[ARRAY_SIZE];
int number_of_records = 0;

int main() {
  char input;
  printf(WELCOME_TEXT);
  while (input != 'Q') {
    printf(PROMPT);
    scanf("%c\n", &input);
    if (input >= 'a' && input <= 'z') 
      input -= 32;
    if (input == 'A') 
      add_person();
    if (input == 'S') 
      search_records();
    if (input != 'A' && input != 'S' && input != 'Q') 
      printf("\n%s",ERROR);
  }
  print_all();
  return 0;
}

void print_person(PERSON *ptr) {
  printf("First name: %s\n", ptr->first_name);
  printf("Last name: %s\n", ptr->last_name);
  printf("Phone Number: %s\n", ptr->phone_number);
  printf("Age: %d\n", ptr->age);
}

void add_person() {
  PERSON *temp = malloc(sizeof(PERSON));
  printf("\nFirst Name - ");
  scanf("%s\n", temp->first_name);
  printf("Last Name - ");
  scanf("%s\n", temp->last_name);
  printf("Phone Number - ");
  scanf("%s\n", temp->phone_number);
  printf("Age - ");
  scanf("%d\n", &temp->age);
  
  records[number_of_records++] = temp;
}

int search_first_name(PERSON *ptr,char* name) {
  int i;
  printf("woah");
  for (i = 0 ; i != number_of_records ; i++) {
    if (strstr(records[i]->first_name, name)) {ptr = records[i]; return 0;}
  }
  return 1;
}

int search_last_name(PERSON *ptr, char* name) {
  int i;
  for (i = 0 ; i != number_of_records ; i++) {
    if (strstr(records[i]->last_name, name)) {ptr = records[i]; return 0;}
  }
  return 1;
}


void search_records() {
  int rc;
  char type;
  char* search_text;
  PERSON *result;

  printf(SEARCH_TEXT);
  rc = scanf("%c\n", &type);
  printf("Input string to search for ");
  scanf("%s\n", search_text);

  if (type >= 'a' && type <= 'z') {type -= 32;}
  if (type == 'F') {
    if (search_first_name(result,search_text)) {
      printf("%s","Error - not found!\n");
      return;
    }
  }
  else if (type == 'L') 
    if (search_last_name(result,search_text)) {
      printf("%s","Error - not found!\n");
      return;
    }
  print_person(result);
}

void print_all() {
  int i;
  printf(PRINT_ALL);
  for (i = 0 ; i != number_of_records ; i++) {
    print_person(records[i]);
    printf("\n");
  }
}

always compile with -Wall (warn all), will tell you where there are norty things.

btw, its picking up \n as the char to read, thats some of the nortyness.

[queball]

Originally posted by MT

always compile with -Wall (warn all), will tell you where there are norty things.

btw, its picking up \n as the char to read, thats some of the nortyness.

Then instead of scanf("%c"), use scanf(" %c").

[djbass]

Personally, I'm a fan of getch() ..particularly as you're only dealing with single character input, it's a lot less messy.

=[DJ Bass]=

[Gayle29uk]

I never like the overhead of printf/scanf/derivatives either, both in terms of size and speed. They so make things simpler though