Thread: Getting a while/if loop to work with struct

I want to get an if or while loop in this struct to keep recording data until terminated. Here's my code it keeps freezing after the first input session is completed.

Code:

  #include <stdio.h>


  /* Define our account structure */
  struct account {


   int invoice_number;
   char *company_name;
   int invoice_date;
   float invoice_amount;
   
   };




  /* Define the variables that use the account structure type */


  struct account ledger;




  int main(void)


  {
    char *q;
    int foef;
    struct account ledger;
    FILE *newacct;
    newacct = fopen("robco.txt", "a+");


    printf("Enter Account Name:");
    scanf("%s", &ledger.company_name);
    printf("Enter Incoive Number:");
    scanf("%d", &ledger.invoice_number);
    printf("Enter Invoice Date:");
    scanf("%d", &ledger.invoice_date);
    printf("Enter Invoice Amount:");
    scanf("%f", &ledger.invoice_amount);
    fprintf(newacct,"\n%s %d %d %f", ledger.company_name,   ledger.invoice_number, ledger.invoice_date,     ledger.invoice_amount);
    fclose(newacct);
    
    do
 {
    fscanf(q,"%s %d %d %f", &ledger.company_name,   &ledger.invoice_number, &ledger.invoice_date,   &ledger.invoice_amount);
    printf("%s %d %d %f", ledger.company_name,   ledger.invoice_number, ledger.invoice_date,   ledger.invoice_amount);
 }
    while(!feof(q));
    
   
 }

Originally Posted by Laerehte

Code:

 do{
    fscanf(q,"%s %d", ledger.last_name, ledger.account_number);
    printf("%s %d", ledger.last_name, ledger.account_number);
}
    while(!feof(q)); // <--------
}

Your loop is waiting for an end of file inicator from the given file stream q. Sadly the q variable is not a file stream. Which would never give it an EOF (thus the infinite loop). I would suggest reading into strstr() from string.h to accomplish what you want.

Also main() should return an int.

Right so I plug newacct where q is and it still goes continuously. However I get no warnings in dev +

So I've made it into a switch case, and it works through expect for my first line skips. I used the switch case in a previous program and I like it. I've been at it for a while now so not sure what I am missing something simple i am sure...thanks for everyone help thus far.

Code:

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


struct account 
{
    char company_name[256];
    int invoice_number;
    int invoice_date;
    float invoice_amount;
    
};


int main() 
{
    char *end;
    char buf[256];
    char y;
    char n;
    char a;
    FILE *newacct;
    struct account ledger;
    newacct = fopen("robco.txt", "a");
    


    printf("Enter Account Name:");
    fgets(ledger.company_name, sizeof(ledger.company_name), stdin);
    ledger.company_name[strlen(ledger.company_name)-1] = '\0';
    printf("Enter Incoive Number:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_number = strtol(buf, &end, 10);
    printf("Enter Invoice Date:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_date = strtol(buf, &end, 10);
    printf("Enter Invoice Amount:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_amount = strtol(buf, &end, 10);
    fprintf(newacct,"%s %d %d %f\n", ledger.company_name, ledger.invoice_number, ledger.invoice_date, ledger.invoice_amount);
	fclose(newacct);


	
	printf("Would you like to enter more data?:");
    scanf("%s", &a);


	switch (a){
	
	case'n':
		
 	printf("Thanks for your entry!"); //should terminate
 	fprintf(newacct,"\n%s %d %d %f", ledger.company_name, ledger.invoice_number, ledger.invoice_date, ledger.invoice_amount);
    fclose(newacct);
    
 	return 0;
 
	case'y':	
	FILE *newacct;
    struct account ledger;
    newacct = fopen("robco.txt", "a");
 		
    printf("Enter Account Name:"); //the line that keeps skipping in every switch case.
    fgets(ledger.company_name, sizeof(ledger.company_name), stdin); //it prints however it skips this input line.
    ledger.company_name[strlen(ledger.company_name)-1] = '\0';
    printf("\nEnter Incoive Number:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_number = strtol(buf, &end, 10);
    printf("Enter Invoice Date:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_date = strtol(buf, &end, 10);
    printf("Enter Invoice Amount:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_amount = strtol(buf, &end, 10);
    fprintf(newacct,"%s %d %d %f\n", ledger.company_name, ledger.invoice_number, ledger.invoice_date, ledger.invoice_amount);
	fclose(newacct);
    
 	break;
}
	printf("Would you like to enter more data?:");
    scanf("%s", &a);


	switch (a){
	
	case'n':
		
 	printf("Thanks for your entry!"); //should terminate
 	fprintf(newacct,"\n%s %d %d %f", ledger.company_name, ledger.invoice_number, ledger.invoice_date, ledger.invoice_amount);
    fclose(newacct);
    
 	return 0;
 
	case'y':
	FILE *newacct;
    struct account ledger;
    newacct = fopen("robco.txt", "a");
 		
    printf("Enter Account Name:");
    fgets(ledger.company_name, sizeof(&ledger.company_name), stdin);
    ledger.company_name[strlen(ledger.company_name)-1] = '\0';
    printf("Enter Incoive Number:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_number = strtol(buf, &end, 10);
    printf("Enter Invoice Date:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_date = strtol(buf, &end, 10);
    printf("Enter Invoice Amount:");
    fgets(buf, sizeof(buf), stdin);
    ledger.invoice_amount = strtol(buf, &end, 10);
    fprintf(newacct,"%s %d %d %f\n", ledger.company_name, ledger.invoice_number, ledger.invoice_date, ledger.invoice_amount);
	fclose(newacct);
    
 	break;
}
}

Originally Posted by Laerehte

Also main() should return an int.

Although sloppy the code given is fully compliant with the C standard and is returning an int (it returns 0 if you don't explicitly have a return). So, yes, it's sloppy and bad style IMO to omit the return for main but it's not undefined or anything

...reaching the } that terminates the main function returns a value of 0.

Originally Posted by mp59

So I've made it into a switch case, and it works through expect for my first line skips. I used the switch case in a previous program and I like it. I've been at it for a while now so not sure what I am missing something simple i am sure...thanks for everyone help thus far.

Why have you got return 0 on line 94?

Originally Posted by Hodor

Although sloppy the code given is fully compliant with the C standard and is returning an int (it returns 0 if you don't explicitly have a return). So, yes, it's sloppy and bad style IMO to omit the return for main but it's not undefined or anything

I will agree it's sloppy I'm still new to it all, plus I've been getting a tad annoyed with it. Whenever I feel I get what I'd like, some small odd problem hits. Right now starting on line 65 and 66 it prints what is the account name however it skips over the input line and doesn't let me input my account name.

Originally Posted by Hodor

Why have you got return 0 on line 94?

I have a return 0 on multiple lines in my case so if you input a 'n' when asked if you'd like to continue input it terminates the program.

Solved thanks.