Using the fscanf() and fprintf() functions

/* 2203.c: Using the fscanf() and fprintf() functions */
#include <stdio.h>

enum {SUCCESS, FAIL,
MAX_NUM = 3,
STR_LEN = 23};
void DataWrite(FILE *fout);
void DataRead(FILE *fin);
int ErrorMsg(char *str);

main(void)
{
    FILE *fptr;
    char filename[]= "strnum.mix";
    int reval = SUCCESS;

    if ((fptr = fopen(filename, "w+")) == NULL){
        reval = ErrorMsg(filename);
    }
    else {
        DataWrite(fptr);
        rewind(fptr);
        DataRead(fptr);
        fclose(fptr);
    }

    return reval;
}
/* function definition */
void DataWrite(FILE *fout)
{
    int i;
    char cities[MAX_NUM][STR_LEN] = {"St.Louis->Houston:","Houston->Dallas:","Dallas->Philadelphia:"};
    int miles[MAX_NUM] = {845,243,1459};

    printf("The data written:\n");
    for (i=0; i<MAX_NUM; i++){
        printf("%-23s %d miles\n", cities[i], miles[i]);
        fprintf(fout, "%s %d", cities[i], miles[i]);
    }
}
/* function definition */
void DataRead(FILE *fin)
{
    int i;
    int miles;
    char cities[STR_LEN];

    printf("\nThe data read:\n");
    for (i=0; i<MAX_NUM; i++){
        fscanf(fin, "%s%d", cities, &miles);
        printf("%-23s %d miles\n", cities, miles);
}
}
/* function definition */
int ErrorMsg(char *str)
{
    printf("Cannot open %s.\n", str);
    return FAIL;
}