Question

I am new to C, and want to read some data from a file.

Actually, I find many reading functions, fgetc, fgets, etc..
But I don’t know which one/combination is the best to read a file with the following format:

0 1500 100.50
1 200     9
2 150     10

I just need to save each row above into a struct with three data members.

I just need to know the best practice to do that, hence I am new to C programming.

Thanks.

Answer 1

Try reading each line using fgets. With each line, you can then use sscanf.

FILE* f = fopen("filename.txt", "r");
if (f) { 
    char linebuff[1024];
    char* line = fgets(linebuff, 1024, f);
    while (line != NULL) {
        int first, second;
        float third;
        if (sscanf(line, "%d %d %g", &first, &second, &third) == 3) {
            // do something with them.. 
        } else {
            // handle the case where it was not matched.
        }
        line = fgets(linebuff, 1024, f);
    }
    fclose(f);
}

This may have errors, but it’s just meant to give you an example of how you might use the functions. Be sure to validate what sscanf returns you.