How to use feof(FILE *f)?

Question

I'm having a hard time with a do-while loop, that is supposed to stop when we reach the end of the file. Here's the loop code:

do  {
    if (pcompanyRow[0] != '#' && pass == 1) {
        strtok(pcompanyRow, ":");
        pcompanyName = strcpy(pcompanyName, strtok(NULL, ""));
        pass = 2;
        fgets(pcompanyRow, 1024, f);
    }
    if (pcompanyRow[0] != '#' && pass == 2) {
        strtok(pcompanyRow, ":");
        pcompanySMSPrice = strcpy(pcompanySMSPrice, strtok(NULL , ""));
        pass = 3;
        fgets(pcompanyRow, 1024 , f);
    }
    if (pcompanyRow[0] != '#' && pass == 3) {
        strtok(pcompanyRow, ":");
        pcompanyMMSPrice = strcpy(pcompanyMMSPrice, strtok(NULL, ""));
        pass = 4;
        fgets(pcompanyRow, 1024, f);
    }
    if (pass == 4)  {
        AppendCompanyNode(pcompanyList, pcompanyName, pcompanySMSPrice, pcompanyMMSPrice);
        pass = 1;
    }
} while (!feof(f));

After running with the debugger, I noticed that all the crash problems I have are because it doesn't go out of this loop even when it reached the whole lines.

How should I write it correctly?

Answer 1

You should never use feof() as the exit indicator for a loop. feof() is TRUE only after the end of file (EOF) is read, not when EOF is reached

Source here. It also explains the problem in detail and how to fix it.