CODEWITHSUNDEEP
cstructfile-iostrtok
Leo Wang
Leo Wang

Reputation: 147

function strtok() and mixed variable type in C

I was trying to read data from a file and inserting the data into a struct array, the file is formatted like so: 

...
0087|www.google.com|2017.08.07 12:13:36
0150|www.yahoo.com|2018.10.06 04:03:12
...

where data types are seprated by '|'s, I then use strtok()to seprate the data, this worked well for both string types timestamp and domain, I was able to get the data stored correctly in the struct, however, for the data type customerid I am only getting the memory address in the struct, how could I solve this? Thanks!

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

struct AccessRecord {       
    int customerID;         
    char domain[256];
    char timestamp[21]; 
    };

struct AccessRecord rc[1000];


int main()
{
    int i = 0; char line[300]; 
    const char s[2] = "|";

    FILE *fd;
    fd = fopen("./example_data.ipb","r");


    while (fgets(line, sizeof(line), fd)) {

        char *token;

        token = strtok(line, s);

        rc[i].customerID = token;
        token = strtok(NULL, s);

        strcpy (rc[i].domain , token);
        token = strtok(NULL, s);


        strcpy (rc[i].timestamp , token);
        token = strtok(NULL, s);

        i++;
    }
    fclose(fd);

    return 0;
}

Upvotes: 0

Views: 155

Answers (1)

paxdiablo
paxdiablo

Reputation: 882586

Note the two different ways you are extracting data:

token = strtok(line, s);
rc[i].customerID = token;       // assignment of char* (to int, so suspect)

token = strtok(NULL, s);
strcpy (rc[i].domain , token);  // string copying

This is despite the fact that both of those are strings. Although the customer ID is numeric data, it is stored as a string and should be treated as such.

In other words, since it is an integer in the structure, you can convert it while reading, such as with:

token = strtok(line, s);
rc[i].customerID = strtol(token, NULL, 10);

Upvotes: 1

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