Question

I have a code that scans all the files in a directory for targeted words, and prints them out into a new file. The problem right now is after the while loop reads a file and stores a variable into the string (ex. customer), if the next file being read does not have the targeted word, it still displays the result stored in the string from the previous file. My goal is to make it display “N/A” if the current file does not have the target word.

I have tried a few ways to clear the string at the end or beginning of the while loop, but none of them work most of them just gives me a coredump error. Running out of ideas, any help would be much appreciated!

Code (shortened for easier reading):

int main(int argc, char** argv)
{   
    char           directory[100];
    char           buff[100];
    char           delims[] = " :=";
    char*          result = NULL;
    char*          customer;
    char*          device;
    char*          buffer;
    int            i = 0;
    DIR*           FD;
    struct dirent* in_file;
    int            c = 0;

    printf("Enter directory:");                                   
    scanf("%s",directory);

    FILE* ft = fopen("workorderlist.csv", "w");    /* Open file to write to*/
    if (ft == NULL)
    {
        puts("Cannot open target file");
        exit(1);
    }

    fprintf (ft, "Work Order,Customer,Device,Test_Prog,Software,DUT_board_id,Corl box\n");

    /* Open Directory */
    if (NULL == (FD = opendir(directory))) 
    {
        puts("Cannot open directory");

        return 1;
    }

    while ((in_file = readdir(FD))) 
    {
        if (!strcmp (in_file->d_name, "."))
        {
            continue;
        }

        if (!strcmp (in_file->d_name, ".."))    
        {
            continue;
        }

        /* Open files to read from  */  
        buffer = (char*)malloc(100);
        sprintf(buffer, "%s/%s", directory, in_file->d_name);

        size_t len = strlen(buffer);
        if (len >= 4 && memcmp(buffer + len - 4, ".wor", 4) == 0)   /* checks if file ends with .wor */
        {
            FILE* fs = fopen(buffer, "r");       /* open file to read */

            if (fs == NULL)
            {
                puts("Cannot open source file");

                return 1;
            }

            /* Scanning each file for targeted words: */
            while (fgets(buff, 100, fs) != NULL)      
            {   
                result = strtok( buff, delims );          
                while (result != NULL)
                {   
                    if ((strcmp(result, "Customer") == 0))
                    { 
                        result = strtok(NULL,delims);  
                        customer = (char*)malloc((strlen(result)+1)*sizeof(char));
                        strcpy(customer, result);
                        for (i = 0; i < strlen(customer) + 1; i++)
                        {
                            if (customer[i] == '\n')
                            {
                                break;
                            }
                        }

                        customer[i] = ' ';
                    }

                    if (strcmp(result, "device") == 0)
                    { 
                        result = strtok(NULL, delims);  
                        device = (char*)malloc((strlen(result) + 1) * sizeof(char));
                        strcpy(device, result);
                        for (i = 0; i < strlen(device) + 1; i++)
                        { 
                            if(device[i] == '\n')
                            {
                                break;
                            }
                        }

                        device[i] = ' ';
                    }

                    result = strtok(NULL,delims);
                }   
            }

            if (customer == '\0')
            {
                customer = "N/A";
            }

            if (device == '\0')
            {
                device = "N/A";
            }

            fprintf(ft, "%s,%s,%s,%s,%s,%s,%s\n", 
                    in_file->d_name, customer, device, testprog, 
                    software, dutboardid, corlbox);

             printf(in_file->d_name);
             printf("\n");
             fclose (fs) ;
             c++;
        }
    }

    printf("Total Workorders Found: %d (Info saved to workorderlist.csv)\n", c);
    fclose(ft);

    return 0;
}

Answer 1

First at all, customer/device are strings. You should not be doing == for it comparison. You can, for example, compare the first char of the string: device[0] == '\0';
You should do string initialization before the loop starts.
You can achieve this by using strcpy with a known value or any other string manipulation function. The value that you use to initialize the string before the loop is the one you gonna test with strcmp or similar later.
Is like with ints or any other C data type, but you need manipulation functions instead.

By the way, haven’t you posted your read file loop in a question here too?

Hope this helps.