friends.txt

128       Pawit               18  175.5 N
12        Phruksa             18  181.5 N

main.c

void main()
{
    FILE *fid;
 
    int i, count;
    long id[100];
    char fname[100][20];
    int age[100];
    double height[100];
    char married[100][2];
 
 
    fid = fopen("friends.txt","r");
 
 
    if(!(fid==NULL))
    {
        i=0;
        while(!feof(fid))
        {
            fscanf(fid,"%ld%s%d%lf%s\n",&id[i],&fname[i],&age[i],&height[i],&married[i]);
            i++;
        }
        count=i;
        fclose(fid);
        printf("%-10s%-20s%-4s%-10s%-10s\n","ID","Name","Age","Height","Married");
 
 
        // Print
        for(i = 0; i < count; i++)
        {
            printf("%-10ld%-20s%-4d%-10.1lf%-10s\n",id[i],fname[i],age[i],height[i],married[i]);
        }
 
        // Update age of Pawit
        age[0] = 20;
 
 
        // Update name of Phruksa
        strcpy(fname[1], "Kularb");
 
 
        // Add new record
        id[count] = 100;
        strcpy(fname[count], "Thanat");
        age[count] = 19;
        height[count] = 190;
        strcpy(married[count], "Y");
        count = count + 1;
 
 
        // Write to file
        fid = fopen("D:\\friends.txt", "w");
        for (i = 0; i < count; i++) {
            fprintf(fid, "%-10ld%-20s%-4d%-6.1lf%1s\n", id[i], fname[i], age[i], height[i], married[i]);
        }
        fclose(fid);
    }
    else printf("Cannot open file.");
    getchar();
}