Thread: input file problem

They're called state machines

Code:

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

int main()
{
    enum { DO_INIT, DO_TIME, DO_COORDS, DO_DATA } state = DO_INIT;
    char buff[BUFSIZ];
    FILE *fp = fopen("words.txt", "r");

    while (fgets(buff, BUFSIZ, fp) != NULL) {
        switch (state) {
        case DO_INIT:
            printf("Init line=%s", buff);
            if (strncmp(buff, "TIME", 4) == 0) {
                state = DO_TIME;
            }
            break;
        case DO_TIME:
            if (strncmp(buff, "COORDINATES", 11) == 0) {
                state = DO_COORDS;
            } else {
                printf("Time line=%s", buff);
            }
            break;
        case DO_COORDS:
            if (strncmp(buff, "DATA", 4) == 0) {
                state = DO_DATA;
            } else {
                printf("Coord line=%s", buff);
            }
            break;
        case DO_DATA:
            printf("Data line=%s", buff);
            break;
        }
    }
    fclose(fp);
    return 0;
}

Just replace the printf() calls with sscanf() converting the data as you see fit.

> what is: "BUFSIZ"
A constant in stdio.h

> and the meaning of the arguments here:
read your manual page on fgets()

> 2. in the "enum" line, what is the purpose of the variables ?
Well you have to name each state. It seemed better than STATE1, STATE2, STATE3
> do I need to give the values ?
No - enum numbers itself.

> 3. does "return 0" mean the "main" doesn't return any value ?
0 means success (as does EXIT_SUCCESS)
EXIT_FAILURE means it failed.
any other values depend on your environment as to what they actually mean to your OS.

> 4. (and the most important) how can I put the "DATA" values of each line into diffrent structures
How abount an array of structs