Segmentation fault ?

[jigamuffin]

Hey. I'm making a system to retrieve data from a .txt file, but I keep getting 'Segmentation fault.' The program will compile but when I try to run it, it will crash. Here is the code, the problem being from fopen to fclose. I used this method before and it worked

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

typedef struct{
        char fname[32];
        char lname[32];
        char address [64];
        char phone [16];
        char email [64];
        char credit_num[16];
        char credit_expiry[16];
        char credit_bsb[4];
        char licence_num[32];
        int ID;
        }customer;

int main(){
    
    customer custData[128];
    int ch;
    char surname[32];
    char fname[32];
    FILE *cust;
    char address[64];
    char num[16];
    char mail[64];
    char crednum[16];
    char expiry[16];
    char bsb[4];
    char licnum[32];
    char line[128];
    char *item;
    int i = 0;
    int reccount = 1;
    int ID;
    

    
    cust = fopen("customer.txt", "r");                    //the problem is from somewhere here
    while(fgets(line,127,cust))
        {
            
            
            item = strtok(line, ";");
            
            strcpy(custData[reccount].fname, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].lname, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].address, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].phone, item);
            item = strtok(NULL, ";");
        
            strcpy(custData[reccount].email, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].credit_num, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].credit_expiry, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].credit_bsb, item);
            item = strtok(NULL, ";");
            
            strcpy(custData[reccount].licence_num, item);
            item = strtok(NULL, ";");
            
            custData[reccount].ID = atoi(item);
            
            reccount++;
            
   }
    fclose(cust);                            //to here
    
    printf("\nEnter customerID> ");
        scanf("%d", &ID);
        for(i=0;i<128;i++){
                if(ID == custData[i].ID){
                       printf("First name> %s\nSurname> %s\nAddress> %s\nPhone Number> %s\nEmail Address> %s\nCredit Card Number> %s\nCredit Card Expiry> %s\nCredit Card BSB> %s\nLicence Number> %s\nCustomer ID> %d\n", custData[i].fname, custData[i].lname,custData[i].address,custData[i].phone,custData[i].email,custData[i].credit_num,custData[i].credit_expiry,custData[i].credit_bsb,custData[i].licence_num,custData[i].ID);
                               }
                               else
                               {
                               printf("CustomerID not found.");
                                                 }
                                       }
               
    }

[Subsonics]

You have no error checking what so ever, this makes it impossible to fail gracefully or prevent the problem, instead you just crash. Some suspects are:

• The file does not exist where you think it does.
• strtok at one time returns NULL which makes strcpy crash
• your file has more than 127 lines, or it has 127 but you start at index 1

[claudiu]

My suspicion is that your problem is the fact that you count your customer records from 1 rather than 0, and presumably you have 128 of them in the file, causing an overflow when reading the last customer data set.

[claudiu]

Damnit Subsonics