Thread: how do you put struct pointers into functions?

This is my struct

Code:

typedef struct{
char first[20];
char last[20];
int nums[6];
}RECORD;

this is my function prototype

Code:

void writeRecord (RECORD* , FILE*, int);

this is my functions

Code:

void writeRecord (RECORD* people, FILE* fp, int num_people){
...................
}

in my main i put

Code:

RECORD* people;

people = (RECORD*) malloc(num_people*sizeof (RECORD));

writeRecord(people, fp, num_people);

can you guys tell me where i'm going wrong.

these are the errors i get in microsoft visual c++ 2008

these all point to the prototype
syntax error: ')'
syntax error: ','
syntax error: missing ')' before '*'
syntax error: missing '{' before '*'

these point to the function
writeRecord: redifinition; different basic types

Originally Posted by SORAKH2756

This is my struct

Code:

typedef struct{
char first[20];
char last[20];
int nums[6];
}RECORD;

this is my function prototype

Code:

void writeRecord (RECORD* , FILE*, int);

this is my functions

Code:

void writeRecord (RECORD* people, FILE* fp, int num_people){
...................
}

in my main i put

Code:

RECORD* people;

people = (RECORD*) malloc(num_people*sizeof (RECORD));

writeRecord(people, fp, num_people);

can you guys tell me where i'm going wrong.

these are the errors i get in microsoft visual c++ 2008

these all point to the prototype
syntax error: ')'
syntax error: ','
syntax error: missing ')' before '*'
syntax error: missing '{' before '*'

these point to the function
writeRecord: redifinition; different basic types

Did you define fp (FILE *fp) somewhere in main()?? It's hard to tell when your program
is in snips with the errors you are getting. Can you post everything?

sure can

Code:

#include <stdlib.h>
#include <stdio.h>

//function prototype
void writeRecord (RECORD* , FILE*, int)

//Enumarated winnings

enum Scenario{

	three = 10,
	four = 100,
	five = 10000,
	six = 1000000
};

//Record struct
typedef struct{
	char first[20];
	char last[20];
	int nums[6];
}RECORD;

main(){
	FILE* fp;
	int num_people,i,WinNums[6] = {0};
	char file_name[20];
	RECORD* people;

	//asks and opens the file the user puts in

	printf("Enter the name of the file with the ticket data.\n");
	scanf("%s",file_name);

	fp = fopen(file_name,"r");

	if(fp == NULL){
		printf("Can't find the file you have entered");
		system("pause");
		exit(-1);
	}

	// Reads the amount of people in lottery and allocates memory

	fscanf(fp,"%i",&num_people);

	people = (RECORD*) malloc(num_people*sizeof (RECORD));


	// Start to put information about people in the Record array people

	writeRecord(people, fp, num_people);


	//Asks user for the winning numbers and error check

	printf("Enter the winning Lottery numbers\n");
	scanf("%i %i %i %i %i %i",&WinNums[0],&WinNums[1],&WinNums[2],&WinNums[3],&WinNums[4],&WinNums[5]);

	while(WinNums[0] > WinNums[1] || WinNums[1] > WinNums[2]|| WinNums[2] > WinNums[3] || WinNums[3] > WinNums[4]||WinNums[4] > WinNums[5]){
		printf("you entered numbers in non ascending order, try again.");
		printf("Enter the winning Lottery numbers\n");
		scanf("%i %i %i %i %i %i",&WinNums[0],&WinNums[1],&WinNums[2],&WinNums[3],&WinNums[4],&WinNums[5]);
	}

	//
	fclose(fp);
	system("pause");
}


void writeRecord ( RECORD* people,FILE* fp,int num_people){
	int i;
	for(i=0; i<num_people;i++){
		fscanf(fp,"%s %s %i %i %i %i %i %i",people[i].last,people[i].first,people[i].nums[0],people[i].nums[1],people[i].nums[2],people[i].nums[3],people[i].nums[4],people[i].nums[5]);
	}
}

wow you're right. I also figured out that I needed to put the struct above the prototype.

Now what i'm having trouble with is this part

Code:

void writeRecord ( RECORD* people,FILE* fp,int num_people){
	int i;
	for(i=0; i<num_people;i++){
		fscanf(fp,"%s %s %i %i %i %i %i %i",people[i].last,people[i].first,people[i].nums[0],people[i].nums[1],people[i].nums[2],people[i].nums[3],people[i].nums[4],people[i].nums[5]);
	}
}

it's reading the name from the file, but it won't read the integers :[

wow you're right. I also figured out that I needed to put the struct above the prototype.

lmao, I don't get that very often on here! I'm sure there will be *someone* that
will argue with the merits of my previous suggestion, putting a ";" after your
function prototype.

ok, easy stuff done... will take some time to look at the rest.

lol yea i think you are wrong, created a lot of errors

Originally Posted by SORAKH2756

lol yea i think you are wrong, created a lot of errors

I did some editing since my last post, read the last one again. I only put "struct" in the
function prototype, but not in the function's arguments.

Anyway I got this puppy to compile & run, I've created a .txt file....

Can you post your winning.txt so that I can test the program?

5
Llewellyn Mark
1 15 19 26 33 46
Young Brian
17 19 33 34 46 47
Cazalas Jonathan
1 4 9 16 25 36
Siu Max
17 19 34 46 47 48
Balci Murat
5 10 17 19 34 47

save that as a input.txt

int WinNums[6] = {0};

Can I ask what you're doing here? I see a 6 element of type int declared,
but I get lost on the initialize part. Shouldn't it be like:

Code:

int WinNums[6] = {0,0,0,0,0,0};

and then placed above main()?

just by initializing it once, it automatically gives it to all of them.
btw i got passed a lot of the coding. now i'm comparing values from the user input and the txt files =P

I don't want to correct your homework .... but here's one hint you might want to pick up on...

Always write your code so that your Main or WinMain functions are at the bottom of the page, not the top. That way you have an organization that will ensure things are known about before they are called... and it makes for much tidier code too. You won't need function prototypes in this structure because everything is defined before it's called. And... most importantly, you will find your code is a lot easier to debug when working from a bottom up structure.

OK, I'm exhausted. One final note, is you use scanf() i.e. reading the file name...
I would change that to gets()... before gets() I wrote another function called "void clear_kb(void)
that should be used before each scanf() if you choose to use scanf().

Also, I'm gravely concerned with my suggestion to add "struct" in the function prototype. I thought function prototypes & function definitions, the arguments should match perfectly.

Also, today I just finished the chapter on file operations... so I'm not strong there. Haven't covered "enum" types yet.

i see, well this is the code i got now

Code:

#include <stdlib.h>
#include <stdio.h>

//Record Struct
typedef struct{
	char first[20];
	char last[20];
	int numbers[6];
}RECORD;

//function prototypes
void writeRecord ( RECORD* , FILE*, int);
void Winners (RECORD*,int,int);

//Enumarated winnings
enum Scenario{

	three = 10,
	four = 100,
	five = 10000,
	six = 1000000
};


main(){
	FILE* fp;
	int num_people,i,WinNums[6] = {0};
	char file_name[20];
	RECORD* people;

	//asks and opens the file the user puts in

	printf("Enter the name of the file with the ticket data.\n");
	scanf("%s",file_name);

	fp = fopen(file_name,"r");

	if(fp == NULL){
		printf("Can't find the file you have entered");
		system("pause");
		exit(-1);
	}

	// Reads the amount of people in lottery and allocates memory

	fscanf(fp,"%i",&num_people);

	people = (RECORD*) malloc(num_people*sizeof (RECORD));


	// Start to put information about people in the Record array people

	writeRecord(people, fp, num_people);


	//Asks user for the winning numbers and error check

	printf("Enter the winning Lottery numbers\n");
	scanf("%i %i %i %i %i %i",&WinNums[0],&WinNums[1],&WinNums[2],&WinNums[3],&WinNums[4],&WinNums[5]);

	while(WinNums[0] > WinNums[1] || WinNums[1] > WinNums[2]|| WinNums[2] > WinNums[3] || WinNums[3] > WinNums[4]||WinNums[4] > WinNums[5]){
		printf("you entered numbers in non ascending order, try again.\n");
		printf("Enter the winning Lottery numbers\n");
		scanf("%i %i %i %i %i %i",&WinNums[0],&WinNums[1],&WinNums[2],&WinNums[3],&WinNums[4],&WinNums[5]);
	}

	//Checks amount of numbers matched and outputs winners
	Winners(people,num_people,WinNums);

	//closes file and free's up the memory allocated
	fclose(fp);
	free(people);

	system("pause");
}


void writeRecord (RECORD* people,FILE* fp,int num_people){
	int i;

	//scanning the file and encoding the data into the struct

	for(i=0; i<num_people;i++){
		fscanf(fp,"%s %s",people[i].last,people[i].first);
		fscanf(fp,"%i",people[i].numbers);
		fscanf(fp,"%i",people[i].numbers+1);
		fscanf(fp,"%i",people[i].numbers+2);
		fscanf(fp,"%i",people[i].numbers+3);
		fscanf(fp,"%i",people[i].numbers+4);
		fscanf(fp,"%i",people[i].numbers+5);
	}
}

void Winners(RECORD* people,int num_people,int WinNums[]){
	int i,j,k,num_matched;

	for(i=0; i < num_people; i++){
		num_matched = 0;
		for(j=0; j<6; j++){
			for(k=0; k<6;k++){
				if(people[i].numbers[j] == WinNums[k]){
					num_matched++;	
				}

			}
			if(num_matched == three){

		}
	}

}

as you can see i'm trying to get all the matches for one profile. I know there is an easier code for it but i forgot.
I also have to use the enum thing which idk how do use :P